JPH08179508A - Radiation sensitive resin composition - Google Patents

Abstract

PURPOSE: To make it possible to form rectangular patterns with high resolution and to improve sensitivity, developability, resolution, etc., by incorporating an alkali-soluble resin, radiation sensitive acid generating agent, crosslinking agent and basic compd. which are respectively specific into the above compsn. CONSTITUTION: This radiation sensitive resin compsn. contains the alkali-soluble resin, the radiation sensitive acid generating agent consisting of at least one kind selected from a bis-sulfonyl diazo methane compd. and imide sulfonate compd., the crosslinking agent consisting of an alkoxymethylated urea compd. and the basic compd. consisting of a trialkyl amine. This alkali-soluble resin is a resin which has a functional group, for example, acidic functional group, exhibiting affinity with an alkaline developer, and is soluble in this alkaline developer. The radiation sensitive acid generating agent is a compd. which generates an acid by sensitizing the radiation to be cast after the formation of the resist film. The crosslinking agent is a compd. capable of crosslinking the alkali-soluble resin in the presence of the acid generated by the irradiation with, for example, radiation.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a radiation-sensitive resin composition. More specifically, especially ultraviolet rays, far ultraviolet rays, X
The present invention relates to a radiation-sensitive resin composition which is useful as a resist suitable for ultrafine processing using radiation such as rays or charged particle rays.

[0002]

2. Description of the Related Art In the field of microfabrication represented by the manufacture of integrated circuits, miniaturization of the processing size in lithography is progressing in order to obtain a higher degree of integration of integrated circuits. A technique capable of stably performing the following fine processing is required. Therefore, it is necessary to accurately form a pattern of 0.5 μm or less in the resist used. Therefore, a lithography technique using shorter wavelength radiation has been studied. Examples of such radiation include ultraviolet rays typified by i rays (365 nm), far ultraviolet rays typified by KrF excimer lasers (248 nm), X rays typified by synchrotron radiation, and charged particle rays typified by electron beams. Etc. In recent years, various resists corresponding to these radiations have been proposed. Of these, a resist that causes a reaction that changes the solubility in a developing solution due to the catalytic action of an acid generated by irradiation of radiation is usually noted. It is called "resist". When these resists are actually used in the integrated circuit manufacturing process, usually, a resist solution is prepared by dissolving the components constituting the “resist” such as the radiation-sensitive component and the film-forming resin component in a solvent, and processing them. It is applied on the substrate to be provided to form a resist film. Next, by irradiating the resist film with radiation to form a pattern suitable for microfabrication, the shape of the pattern at this time has an important influence on the accuracy of microfabrication, and a rectangular shape is preferred. There is. However, the conventional chemically amplified negative resist has a low transmittance of the resist film against radiation, and when the resist film is irradiated with radiation, the radiation is not sufficiently irradiated to the lower end of the resist, and as a result, the side of the resist pattern is developed during development. The resist pattern obtained by etching has an inverse taper shape, and it is difficult to obtain the required rectangular pattern. Further, such a phenomenon is not preferable because it causes a decrease in pattern resolution and causes a meandering of the pattern.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a novel radiation sensitive resin composition, which has a wide tolerance for the radiation dose of a resist film and forms a rectangular pattern with high resolution. And a radiation sensitive resin composition suitable as a chemically amplified negative resist which is excellent in sensitivity, developability, resolution and the like. Another object of the present invention is to effectively suppress side etching phenomenon and meandering of a resist pattern at the time of development, and is suitable as a chemically amplified negative resist that can be effectively used for irradiation of radiation having a wavelength of deep ultraviolet rays or less. Another object of the present invention is to provide a radiation-sensitive resin composition. Other objects and effects of the present invention will be apparent from the following description.

[0004]

According to the present invention, the above objects and effects of the present invention are: A) an alkali-soluble resin; B)
This is achieved by a radiation-sensitive resin composition (hereinafter referred to as "resist composition"), which comprises a radiation-sensitive acid generator, C) a crosslinking agent and D) a basic compound.

Further, the above objects and effects of the present invention are that the radiation-sensitive acid generator contains a radiation-sensitive acid generator comprising at least one selected from a bissulfonyldiazomethane compound and an imidosulfonate compound. Achieved by the composition.

Further, the above objects and effects of the present invention are achieved by a radiation-sensitive resin composition in which the crosslinking agent contains a crosslinking agent composed of an alkoxymethylated urea compound.

The above objects and effects of the present invention are achieved by a radiation-sensitive resin composition in which the basic compound contains a basic compound consisting of trialkylamine. Hereinafter, each component constituting this resist composition will be described.

Alkali-Soluble Resin The alkali-soluble resin used in the resist composition has a functional group having an affinity with an alkali developing solution, for example, an acidic functional group such as a phenolic hydroxyl group and a carboxyl group, and is compatible with the alkali developing solution. It is a resin that is soluble. As such an alkali-soluble resin, at least one monomer having an acidic functional group represented by polyhydroxystyrene, poly (meth) acrylic acid and the like (hereinafter referred to as “monomer (a)”). The addition polymerization type resin (hereinafter, simply referred to as "addition polymerization type resin") having a repeating unit in which the polymerizable double bond is cleaved.

Examples of the addition polymerization resin include hydroxystyrene, hydroxy-α-methylstyrene, vinylbenzoic acid, carboxymethylstyrene, carboxymethoxystyrene, (meth) acrylic acid, crotonic acid, maleic acid, itaconic acid, citraconic acid. , Mesaconic acid, cinnamic acid, etc., addition polymerization resin having a repeating unit in which at least one polymerizable double bond of the monomer (a) having an acidic functional group such as phenolic hydroxyl group or carboxyl group is cleaved Is preferred. Specific examples of such a monomer (a) include (i) o-hydroxystyrene, m-hydroxystyrene, p-hydroxystyrene, 3-chloro-4-hydroxystyrene, 4-chloro-3. -Hydroxystyrene,
2-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,
3-styryl-4-hydroxystyrene, 3-vinyl-
4-hydroxystyrene, 3-propenyl-4-hydroxystyrene, 3-cumyl-4-hydroxystyrene,
2-methyl-4-hydroxystyrene, 2,6-dimethyl-4-hydroxystyrene, o-hydroxy-α-methylstyrene, m-hydroxy-α-methylstyrene,
Monomers having phenolic hydroxyl groups such as p-hydroxy-α-methylstyrene, vinylbenzoic acid, carboxymethylstyrene, carboxymethoxystyrene; (ii) acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, citracone Examples thereof include monomers having a carboxyl group such as acid, mesaconic acid, and cinnamic acid.

The addition polymerization resin is the monomer (a).
The polymerizable double bond of may be composed only of the repeating unit cleaved, but as long as the resin produced is alkali-soluble, if necessary, a monomer having no acidic functional group (hereinafter, " It may further have another repeating unit in which the polymerizable double bond of the monomer (b) ”is cleaved. Specific examples of the monomer (b) include (iii) aromatic vinyl compounds such as styrene, p-methylstyrene, α-methylstyrene, chlorostyrene, methoxystyrene, vinylaniline, and vinylnaphthalene. (Iv) methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, t-butyl (meth) acrylate, glycidyl (meth) acrylate,
(Meth) acryloyloxy group-containing compound such as benzyl (meth) acrylate; (v) Aliphatic vinyl compound such as methoxyvinyl, t-butoxyvinyl, vinyl acetate; (vi) (meth) acrylonitrile, crotonnitrile, maleinnitrile , Fumaronitrile, mesacone nitrile, citracon nitrile, itacone nitrile, (meth) acrylamide, crotonamide, malein amide, fumaramide, mesaconamide, citracone amide, itacone amide, vinyl pyridine, vinyl-ε-caprolactam, vinyl pyrrolidone, vinyl imidazole, etc. The nitrogen-containing compound which has a polymerizable double bond can be mentioned.

In the present invention, for the purpose of appropriately adjusting the alkali solubility of the resist film in an alkali developing solution,
It is particularly preferable to use an addition polymerization resin obtained from the monomer (a) and the monomer (b) as the alkali-soluble resin. The content of the repeating unit having an acidic functional group in such an addition-polymerized resin cannot be unconditionally defined depending on the type of other repeating units contained as necessary, but is usually 15 to 95 mol%, Preferably 20-
It is 80 mol%.

Further, the addition polymerization resin may be obtained by addition polymerization of the monomer (a), for example, t-
A polymerizable double bond of a monomer having a functional group in which a hydrogen atom of a phenolic hydroxyl group or a hydrogen atom of a carboxyl group is substituted with a protective group such as a butyl group, an acetyl group, a t-butoxycarbonyl group, and a trialkylsilyl group. It is also possible to obtain an objective addition polymerization resin by hydrolyzing the protective group after obtaining an addition polymerization resin having a repeating unit in which is cleaved. Specific examples of the monomer forming such a repeating unit include (viii) phenolic hydroxyl groups such as pt-butoxystyrene, pt-butoxycarbonyloxystyrene, and p-trimethylsilyloxystyrene. Monomers Protected by Protecting Group; (ix) t-butyl acrylate, t-butyl methacrylate, and other carboxyl group-protected monomers.

The addition polymerization for producing the above-mentioned addition-polymerization resin is carried out by a radical polymerization initiator, an anion depending on the kind of the monomer (a), the monomer (b) used as necessary and the reaction medium. A polymerization initiator such as a polymerization catalyst, a coordinated anionic polymerization catalyst, or a cationic polymerization catalyst or a polymerization catalyst is appropriately selected, and bulk polymerization, solution polymerization, precipitation polymerization, emulsion polymerization, suspension polymerization, bulk-suspension polymerization or the like is appropriately selected. Can be carried out in a polymerized form of

The alkali-soluble resin of the present invention can be used alone or in admixture of two or more. Further, the alkali-soluble resin optionally has a condensation unit having a repeating unit composed of at least one monomer having an acidic functional group and a monomer capable of being condensed with the monomer, which is represented by a novolac resin. A condensation polymerization resin having a polymerization repeating unit (hereinafter referred to as "condensation polymerization resin") can be mixed and used. The condensation-polymerized resin may be composed of, for example, only a novolac resin unit, but may further contain other condensation-polymerized units as long as the produced resin is alkali-soluble. Such a condensation-polymer resin contains one or more phenols and one or more aldehydes, optionally together with a condensation-polymerization component capable of forming another condensation-polymer repeating unit, in the presence of an acidic catalyst, water. It can be produced by condensation polymerization or cocondensation polymerization in a medium or a mixed medium of water and a hydrophilic solvent.

Examples of the phenols include o-cresol, m-cresol, p-cresol and 2,3-
Xylenol, 2,4-xylenol, 2,5-xylenol, 3,4-xylenol, 3,5-xylenol, 2,3,5-trimethylphenol, 3,4,5-
Examples include trimethylphenol and the like. Examples of the aldehydes include formaldehyde, trioxane, paraformaldehyde, benzaldehyde, acetaldehyde, propylaldehyde and phenylaldehyde.

When the alkali-soluble resin has a repeating unit containing a carbon-carbon unsaturated bond, it can be used as a hydrogenated product. In this case, the hydrogenation ratio is usually 70% or less, preferably 50% or less, and more preferably 40% or less of the carbon-carbon unsaturated bond contained in the repeating unit. When the hydrogenation rate exceeds 70%, the developability of the alkali-soluble resin with an alkali developing solution tends to decrease.

The content of the repeating unit having an average acidic functional group in the alkali-soluble resin is determined by the kinds of other repeating units contained as necessary, the kinds of alkali-soluble resin to be mixed, the composition ratio, and the molecular weight. However, it is usually 15 to 100 mol%, more preferably 20 to 100 mol%. The polystyrene-equivalent weight average molecular weight (hereinafter referred to as “Mw”) of the alkali-soluble resin measured by gel permeation chromatography varies depending on desired properties of the resist composition, but is preferably 2,000 to 100. 1,000, more preferably 2,000 to 30,000. Mw is 2,
When it is less than 000, the film-forming property tends to deteriorate, and when Mw exceeds 30,000, the developability and resolution tend to deteriorate. The alkali-soluble resin of the present invention may be used alone or as a mixture of two or more addition-polymerization resins having different composition ratios and molecular weights, and if necessary, blending a condensation-polymerization resin. it can. As the alkali-soluble resin used in the resist composition of the present invention, an addition polymerization resin of hydroxystyrene and an addition polymerization resin of hydroxystyrene and styrene are particularly preferable. P-hydroxystyrene is preferable as the hydroxystyrene used for these addition polymerization resins.

Radiation-Sensitive Acid Generator The radiation-sensitive acid generator used in the present invention is a compound which generates an acid in response to the radiation applied after the formation of the resist film. Examples of such a compound include: For example, a sulfone compound, a sulfonate compound, etc. can be mentioned. More specifically, the following compounds can be mentioned.

Sulfone Compound Examples of the sulfone compound include β-ketosulfone, β
-Sulfonyl sulfone, bissulfonyl methane and their α-diazo compounds can be mentioned. Specific examples thereof include phenacylphenyl sulfone, mesitylphenacyl sulfone, bis (phenylsulfonyl) methane, bis (phenylsulfonyl) diazomethane, bis (cyclohexylsulfonyl) diazomethane, and 4-trisphenacylsulfone.

Sulfonic Acid Ester Compound Examples of the sulfonic acid ester compound include alkyl sulfonic acid ester, haloalkyl sulfonic acid ester,
Aryl sulfonate, imino sulfonate, imido sulfonate, etc. can be mentioned. Specifically, benzoin tosylate, pyrogallol tris triflate, pyrogallol methanesulfonic acid triester,
Nitrobenzyl-9,10-diethoxyanthracene-
2-sulfonate etc. can be mentioned.

In the resist composition of the present invention, the radiation-sensitive acid generator is preferably the above-mentioned sulfone compound and / or sulfonate compound, and the particularly preferable radiation-sensitive acid generator is the sulfone compound, which is a bissulfonyldiazomethane compound or The sulfonic acid ester compound contains imidosulfonate.

The bissulfonyldiazomethane compound is a compound represented by the following formula (1).

[0023]

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R ¹ and R ² are each a substituted or unsubstituted perhaloalkyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted Is a cycloalkenyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted aralkyl group.

The imidosulfonate compound is a compound represented by the following formula (2).

[0026]

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Here, R ³ is a divalent organic group,
⁴ is a substituted or unsubstituted perhaloalkyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted cycloalkenyl group, a substituted or unsubstituted Is an organic group selected from the aryl group and a substituted or unsubstituted aralkyl group.

In the above formulas (1) and (2),
“Substituted” means that each organic group is, for example, a nitro group, a cyano group, an amino group, a hydroxyl group, a vinyl group, an alkoxyl group,
It means having a substituent such as a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc.). In the above formulas (1) and (2), examples of the halogen atom in the substituted or unsubstituted perhaloalkyl group include a chlorine atom and a bromine atom. Examples of such a perhaloalkyl group include a trichloromethyl group, a trifluoromethyl group, a perchloroethyl group, a perfluoroethyl group, a perfluoropropyl group,
Carbon number of perfluorobutyl group, perfluoropentyl group, perfluorohexyl group, perfluorooctyl group, perfluorononyl group, perfluorodecyl group, etc. is 1
To 12 perhaloalkyl groups can be mentioned. Further, in the above formulas (1) and (2), examples of the substituted or unsubstituted alkyl group include a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms such as a methyl group, an ethyl group, a propyl group and a butyl group. Can be mentioned. In the above formulas (1) and (2), the substituted or unsubstituted cycloalkyl group is a cyclobutyl group, a cyclopentyl group,
In addition to a cyclohexyl group and the like, there can be mentioned a substituted or unsubstituted cycloalkyl group having a carbon number of 3 to 12 such as a bicycloalkyl group such as a norbornyl group or a camfanyl group. In the above formulas (1) and (2), the substituted or unsubstituted alkenyl group has 2 to 1 carbon atoms such as ethynyl group, propylenyl group, butenyl group and butadienyl group.
Mention may be made of two substituted or unsubstituted alkenyl groups. In the above formulas (1) and (2), examples of the substituted or unsubstituted cycloalkenyl group include a substituted or unsubstituted cycloalkenyl group having 3 to 12 carbon atoms such as a cyclopentenyl group and a cyclohexenyl group. it can. In the above formulas (1) and (2), the substituted or unsubstituted aryl group includes a phenyl group, a biphenyl group, a naphthyl group, an anthryl group, a phenanthryl group, a methylphenyl group, an ethylphenyl group, a methoxyphenyl group, and a chlorophenyl group. Group, hydroxyphenyl group, methylnaphthyl group, ethylnaphthyl group, methoxynaphthyl group,
6 carbon atoms such as chloronaphthyl group and hydroxynaphthyl group
There may be mentioned ~ 18 substituted or unsubstituted aryl groups. In the above formulas (1) and (2), the substituted or unsubstituted aralkyl group is a substituted or unsubstituted aralkyl group having 7 to 18 carbon atoms such as benzyl group, phenylpropyl group, diphenylmethyl group, naphthylmethyl group and the like. A group can be mentioned.

In the above formula (2), the divalent organic group is a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylene group, a substituted or unsubstituted polycycloalkylene group, a substituted or unsubstituted And a substituted or unsubstituted cycloalkenylene group, a substituted or unsubstituted polycycloalkenylene group, a substituted or unsubstituted arylene group, a substituted or unsubstituted aralkylene group, and the like.

Examples of the substituted or unsubstituted alkylene group include substituted or unsubstituted alkylene groups having 1 to 12 carbon atoms such as methylene group, ethylene group, propylene group and butylene group. The substituted or unsubstituted cycloalkylene group, a cyclopentylene group,
Examples thereof include a substituted or unsubstituted cycloalkylene group having 3 to 12 carbon atoms in the cyclohexylene group. Examples of the substituted or unsubstituted polycycloalkylene group include a substituted or unsubstituted polycycloalkylene residue having 5 to 18 carbon atoms, which is obtained by removing two hydrogen atoms from a polycycloalkane such as norbornane or camphane. be able to. In particular, as a special example of a polycycloalkylene group,
A tetravalent organic group capable of having two imidosulfonate groups, such as 2,3,5 of methylcyclopentane
A compound excluding the hydrogen atom at the 1'-position may be represented by the following formula (3).

[0031]

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Examples of the substituted or unsubstituted alkenylene group include substituted or unsubstituted alkenylene groups having 2 to 12 carbon atoms such as ethynylene group, propenylene group and butenylene group. Examples of the substituted or unsubstituted cycloalkenylene group include a cycloalkene or a cycloalkyldiene such as cyclobutene, cyclobutadiene, cyclohexene, and cyclohexadiene, which is a substituted or unsubstituted cycloalkyl having 3 to 12 carbon atoms. Mention may be made of alkenylene residues. The substituted or unsubstituted polycycloalkenylene group is a substituted or unsubstituted C5 to C18 having two hydrogen atoms removed from a polycycloalkene or polycycloalkyldiene such as norbornene, norbornadiene, bornene or bornadiene. The polycycloalkenylene residue of can be mentioned. Examples of the substituted or unsubstituted arylene group include a substituted or unsubstituted arylene group having 6 to 18 carbon atoms such as a phenylene group, a naphthylene group and an anthranylene group. Examples of the substituted or unsubstituted aralkylene group include a substituted or unsubstituted aralkylene group having 7 to 18 carbon atoms such as phenylenemethylene group and phenyleneethylene group.

Specific examples of the compound represented by the above formula (1) include compounds represented by the following formula (4) or formula (5).

[0034]

[Chemical 4]

[0035]

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Specific examples of the compound represented by the above formula (2) include compounds represented by the following formulas (6) to (11).

[0037]

[Chemical 6]

[0038]

[Chemical 7]

[0039]

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[0040]

[Chemical 9]

[0041]

[Chemical 10]

[0042]

[Chemical 11]

In the resist composition of the present invention, the radiation-sensitive acid generator may be used alone or in admixture of two or more. If necessary, the radiation-sensitive acid generator having a structure other than the radiation-sensitive acid generator (hereinafter,
It is referred to as "acid generator (b)". ), For example, an onium salt compound, a halogen-containing compound, a quinonediazide compound or the like can be mixed and used. In this case, the amount of the acid generator (b) added is 50% by weight or less, preferably 30% by weight or less, based on the total amount of the radiation-sensitive acid generator. The mixing ratio of the alkali-soluble resin and the radiation-sensitive acid generator in the resist composition is 10
The radiation-sensitive acid generator is preferably 0.01 to 20 parts by weight, more preferably 0.1 to 10 parts by weight per 0 parts by weight.
Parts by weight. The amount of the radiation-sensitive acid generator compounded is 0.0
If the amount is outside the range of 1 to 20 parts by weight, the obtained pattern shape tends to be defective.

Crosslinking Agent The crosslinking agent used in the resist composition of the present invention is
A compound capable of cross-linking an alkali-soluble resin in the presence of an acid, for example, an acid generated by irradiation with radiation. Examples of such a cross-linking agent include compounds having one or more kinds of substituents (hereinafter referred to as "cross-linkable substituents") having cross-linking reactivity with an alkali-soluble resin.

Specific examples of such a crosslinkable substituent include (i) a hydroxyalkyl group, an alkoxyalkyl group,
Hydroxyalkyl group such as acetoxyalkyl group or its derivative; (ii) Carbonyl group such as formyl group or carboxyalkyl group or its derivative; (iii) Dimethylaminomethyl group, diethylaminomethyl group, dimethylolaminomethyl group, diethylolamino group Nitrogen-containing group-containing substituents such as methyl group and morpholinomethyl group; (iv) Glycidyl group-containing substituents such as glycidyl ether group, glycidyl ester group, glycidylamino group; (v) Benzyloxymethyl group, benzoyloxymethyl group Aromatic derivatives such as allyloxyalkyl groups and aralkyloxyalkyl groups; and (vi) polymerizable multiple bond-containing substituents such as vinyl groups and isopropenyl groups. As the crosslinkable substituent of the crosslinking agent of the present invention, a hydroxyalkyl group, an alkoxyalkyl group and the like are preferable, and an alkoxymethyl group is particularly preferable.

Examples of the crosslinking agent having a crosslinkable substituent include (i) a methylol group-containing melamine compound, a methylol group-containing benzoguanamine compound, a methylol group-containing urea compound, a methylol group-containing glycoluril compound, and a methylol group-containing phenol compound. (Ii) Alkoxyalkyl group-containing melamine compounds, alkoxyalkyl group-containing benzoguanamine compounds, alkoxyalkyl group-containing urea compounds, alkoxyalkyl group-containing glycoluril compounds, alkoxyalkyl group-containing phenol compounds and the like. Compound (iii) Carboxymethyl group-containing melamine compound, Carboxymethyl group-containing benzoguanamine compound, Carboxymethyl group-containing urea compound, Carboxy Carboxymethyl group-containing compounds such as chill group-containing glycoluril compounds and carboxymethyl group-containing phenol compounds; (iv) Bisphenol A epoxy compounds, bisphenol F epoxy compounds, bisphenol S epoxy compounds, novolac resin epoxy compounds, resole resins Examples thereof include epoxy compounds such as epoxy compounds and poly (hydroxystyrene) epoxy compounds.

In the resist composition of the present invention, the crosslinking agent is preferably an alkoxymethylated urea compound, and may be a resin in which the alkoxymethylated urea compound is condensed. As a particularly preferable crosslinking agent, an alkoxymethylated urea compound represented by the following formula (12) can be mentioned.

[0048]

[Chemical 12]

Here, R ⁵ is an alkyl group having 1 to 4 carbon atoms.

In the above formula (12), examples of the alkyl group include a methyl group, an ethyl group, a propyl group and a butyl group. The cross-linking agent, for example, after condensation reaction of a urea compound and formalin to introduce a methylol group, further etherified with lower alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol, and then the reaction solution is cooled. It can be obtained by recovering the compound that precipitates or the resin thereof. The cross-linking agent can also be obtained as a commercial product such as CYMEL (trade name, manufactured by Mitsui Cyanamid) and Nicalad (manufactured by Sanwa Chemical Co., Ltd.).

As the cross-linking agent, a resin in which the cross-linking substituent is introduced into the acidic functional group in the alkali-soluble resin to impart the property as a cross-linking agent can be used. In that case, the introduction rate of the crosslinkable substituent is usually 5 to 60 mol%, preferably 10 to 50 mol%, and more preferably 1 with respect to the total acidic functional groups in the alkali-soluble resin.
It is adjusted to 5 to 40 mol%. When the introduction rate of the crosslinkable substituent is less than 5 mol%, it becomes difficult to cause a sufficient cross-linking reaction, the remaining film rate is lowered, and the pattern swelling phenomenon and meandering are likely to occur. Then, the alkali solubility of the alkali-soluble resin is lowered, and the developability tends to deteriorate.

In the resist composition of the present invention, the crosslinking agent may be used alone or in combination of two or more kinds. The mixing ratio of the alkali-soluble resin and the crosslinking agent in the resist composition is preferably 5 to 100 parts by weight, more preferably 10 to 70 parts by weight, and particularly preferably 10 to 5 parts by weight per 100 parts by weight of the alkali-soluble resin.
0 parts by weight. If the amount of the crosslinking agent is less than 5 parts by weight,
The swelling phenomenon may occur due to insufficient crosslinking reaction.
If it exceeds 100 parts by weight, it tends to be difficult to form a good pattern.

Basic Compound The basic compound in the present invention suppresses the diffusion phenomenon of the acid generated from the radiation-sensitive acid generator by the irradiation of the radiation in the resist film, and the unfavorable chemistry in the unirradiated area of the radiation. It is a compound added to a resist composition for the purpose of controlling the reaction. By using such a basic compound, it is possible to improve the shape of the formed pattern, the dimensional fidelity to the mask dimension, and the like.

As such a basic compound, a nitrogen-containing basic compound can be preferably used. Specifically, for example, ammonia, trimethylamine, triethylamine, tri-n-propylamine, triisopropylamine, tri-n-butylamine, triisobutylamine, tri-tert-butylamine, trihexylamine, trioctylamine, aniline, N -Methylaniline, N, N-dimethylaniline, 2-methylaniline,
3-methylaniline, 4-methylaniline, 4-nitroaniline, 1-naphthylamine, 2-naphthylamine,
Diphenylamine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, pyrrolidone, piperidine, imidazole, 4-methylimidazole, 4-
Methyl-2-phenylimidazole, thiabendazole, pyridine, 2-methylpyridine, 4-ethylpyridine, 1-methyl-4-phenylpyridine, 2- (1-ethylpropyl) pyridine, nicotinic acid amide, dibenzoylthiamine, tetrabutyric acid Ribofuramine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 4,4'-diaminobenzophenone, 4,4 '
-Diaminodiphenylamine, 2,2-bis (4-aminophenyl) propane, 2- (3-aminophenyl)-
2- (4-aminophenyl) propane, 2- (4-aminophenyl) -2- (3-hydroxyphenyl) propane, 2- (4-aminophenyl) -2- (4-hydroxyphenyl) propane, 1, 4-bis [1- (4-aminophenyl) -1-methylethyl] benzene, 1,3-
Bis [1- (4-aminophenyl) -1-methylethyl] benzene, dimethyl-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate of succinate, Poly {[6- (1,1,
3,3-Tetramethylbutyl) imino-1,3,5-triazine-2,4-diyl] [(2,2,6,6-tetramethyl-4-piperidiyl) imino] hexamethylene [(2,2 , 6,6-Tetramethyl-4-piperidiyl) imino]}, 2- (3,5-di-t-butyl-4-
Hydroxybenzyl) -2-n-butylmalonate bis (1,2,2,6,6-pentamethyl-4-piperidiyl) and the like can be mentioned.

These basic compounds may be used alone or in the form of 2
A mixture of two or more species can be used. Particularly preferred basic compounds include trialkylamines, and more preferred trialkylamines include tri-n-butylamine, trihexylamine, trioctylamine and the like. The amount of the basic compound to be added is usually 0.01 parts by weight or more and 10 parts by weight per 100 parts by weight of the alkali-soluble resin in the resist composition.
The amount is not more than 0.01 part by weight, preferably not less than 0.01 part by weight and not more than 5 parts by weight. When the amount of the basic compound is 0.01 part by weight or less, the pattern shape and dimensional fidelity may be deteriorated depending on the process conditions, and when it exceeds 10 parts by weight, the sensitivity is lowered and the developability of the radiation irradiated part is deteriorated. Tend to do.

Various Additives Various additives such as a dissolution inhibitor, a dissolution accelerator, a sensitizer, and a surfactant can be added to the resist composition of the present invention, if necessary.

When the alkali-soluble resin has an excessively high alkali-solubility, the dissolution inhibitor reduces the alkali-dissolving rate of the alkali-soluble resin in an alkali developing solution to impart appropriate solubility during alkali development. ,
It is a compound added to the resist composition. The dissolution inhibitor is preferably one that does not chemically change in processes such as baking of the resist film, irradiation with radiation, and development. Examples of such a dissolution inhibitor include aromatic compounds such as naphthalene, phenanthrene, and anthracene; ketones such as acetophenone, benzophenone, and phenylnaphthyl ketone; methylphenyl sulfone, diphenyl sulfone,
Examples thereof include sulfones such as dinaphthyl sulfone. These dissolution inhibitors may be used alone or in admixture of two or more. The amount of the dissolution inhibitor blended can be appropriately selected depending on the alkali-soluble resin used in the resist composition.
Usually 50 parts by weight or less, preferably 30 parts by weight
It is less than or equal to parts by weight.

The above-mentioned dissolution accelerator enhances the rate of alkali dissolution of the alkali-soluble resin in the alkali developer when the alkali-solubility of the alkali-soluble resin is too low,
It is a compound added to a resist composition in order to impart appropriate solubility during alkali development. The dissolution accelerator is preferably one that does not chemically change in processes such as baking the resist film, irradiation with radiation, and development. As such a dissolution accelerator, for example, a low molecular weight phenol compound having a benzene ring of about 2 to 6 can be mentioned. Specific examples of such a phenol compound include compounds such as bisphenol and tris (hydroxyphenyl) methane. These dissolution promoters can be used alone or in admixture of two or more.
The blending amount of the dissolution accelerator can be appropriately selected depending on the alkali-soluble resin used in the resist composition,
It is usually 50 parts by weight or less, preferably 30 parts by weight or less, per 100 parts by weight of the alkali-soluble resin.

The sensitizer has the function of absorbing the energy of radiation and transmitting the energy to the radiation-sensitive acid generator, thereby increasing the amount of acid produced. It has the effect of improving the apparent sensitivity of the resist obtained using the composition. Examples of preferable sensitizers include ketones, benzenes, acetophenones, benzophenones, naphthalenes, biacetyls,
Examples include eosin, rose bengal, pyrenes, anthracenes, and phenothiazines. These sensitizers can be used alone or in admixture of two or more.
The compounding amount of the sensitizer is usually 50 parts by weight or less, preferably 30 parts by weight or less, per 100 parts by weight of the alkali-soluble resin in the resist composition.

The above-mentioned surfactant exhibits an action of improving the coatability and striation of the resist composition, the developability of the resist and the like. Examples of such a surfactant include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene nonyl phenyl ether, polyethylene glycol dilaurate, polyethylene glycol distearate. In addition to the rate, the product name is KP341 (produced by Shin-Etsu Chemical Co., Ltd.), Polyflow No. 75, no. 95
(Manufactured by Kyoeisha Yushi Kagaku Kogyo Co., Ltd.)
F303, EF352, (manufactured by Tochem Products), Megafac F171, F172, F173 (manufactured by Dainippon Ink and Chemicals Incorporated), Florard FC430, FC431
(Made by Sumitomo 3M), Asahi Guard AG710, Surflon S-382, SC-101, SC-102, SC
-103, SC-104, SC-105, SC-106
(Made by Asahi Glass) and the like. These surfactants may be used alone or in admixture of two or more. The content of the surfactant is usually 2 parts by weight or less based on 100 parts by weight of the alkali-soluble resin in the resist composition.

Further, by further blending a dye or a pigment, the latent image on the radiation-irradiated portion can be visualized to mitigate the effect of halation at the time of radiation irradiation, and by blending an adhesion aid, a latent image on the substrate can be formed. Adhesion can be improved. Other additives include antihalation agents, storage stabilizers, antifoaming agents, and the like. Specifically, as the antihalation agent, 4-hydroxy-
4'-methyl chalcone etc. can be mentioned.

Solvent The resist composition of the present invention is dissolved in a solvent and used as a resist solution. Examples of the solvent used in the resist composition of the present invention include (i) ethylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, and ethylene glycol monobutyl ether; ) Ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate and other ethylene glycol monoalkyl ether acetates; (iii) diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether , Diethylene glycol dib (Iv) Propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, and propylene glycol monobutyl ether; (v) Propylene glycol dimethyl ether, propylene glycol Propylene glycol dialkyl ethers such as diethyl ether, propylene glycol dipropyl ether and propylene glycol dibutyl ether; (vi) Propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobub Propylene glycol monoalkyl ether acetates such as ether acetate; (vii) methyl lactate, ethyl lactate, n- propyl, isopropyl lactate, lactate n- butyl, isobutyl lactate, n- amyl lactate esters such as lactic acid isoamyl;

(Viii) Methyl formate, ethyl formate, n-propyl formate, isopropyl formate, n-butyl formate,
Isobutyl formate, n-amyl formate, isoamyl formate, methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, n-amyl acetate, isoamyl acetate, n-hexyl acetate, methyl propionate, Aliphatic carboxylic acids such as ethyl propionate, n-propyl propionate, isopropyl propionate, n-butyl propionate, isobutyl propionate, methyl butyrate, ethyl butyrate, n-propyl butyrate, isopropyl butyrate, n-butyl butyrate, isobutyl butyrate Acid esters; (ix) ethyl hydroxyacetate, 2-hydroxy-2-
Ethyl methyl propionate, methyl 2-hydroxy-3-methylbutyrate, ethyl methoxyacetate, ethyl ethoxyacetate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate,
Ethyl 3-ethoxypropionate, 3-methoxy-2-
Methyl methyl propionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3
Other esters such as butyl-3-methyl-3-methoxypropionate, butyl-3-methyl-3-methoxybutyrate, methyl acetoacetate, ethyl acetoacetate, methyl pyruvate, ethyl pyruvate; (x) toluene, xylene, etc. Aromatic hydrocarbons; (xi) methyl ethyl ketone, methyl propyl ketone,
Ketones such as methylbutylketone, 2-heptanone, 3-heptanone, 4-heptanone, cyclohexanone; (xii) N-methylformamide, N, N-dimethylformamide, N-methylacetamide, N, N-dimethylacetamide, N -Amides such as methylpyrrolidone; and (xiii) lactones such as γ-butyrolactone.

If necessary, these solvents may also be added.
Benzyl ethyl ether, dihexyl ether, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, isophorone, caproic acid, caprylic acid, 1-octanol, 1-nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate, shu It is also possible to add a high boiling solvent such as diethyl acid, diethyl maleate, ethylene carbonate or propylene carbonate. These solvents may be used alone or in admixture of two or more. The amount of all the solvents is usually 20 to 3,000 parts by weight, preferably 50 to 3,0 parts by weight per 100 parts by weight of the alkali-soluble resin in the resist composition.
00 parts by weight, more preferably 100 to 2,000 parts by weight.

The solution of the resist composition of the present invention is, for example, a solution having a solid content concentration of 5 to 50% by weight, which is the total of all resist compositions in the resist composition solution, for example, a pore size of 0.2 μm.
It is prepared by filtering with a filter of about m. When forming a resist pattern from the resist composition of the present invention, a solution of the resist composition, spin coating,
A resist coating is formed by applying it onto a substrate such as a silicon wafer or a wafer covered with aluminum by means such as cast coating or roll coating, and the resist coating is irradiated with radiation to form a desired pattern. Irradiate. The radiation used at that time depends on the type of the radiation-sensitive acid generator used, such as ultraviolet rays such as i-rays, far ultraviolet rays such as excimer lasers, X-rays such as synchrotron radiation, and charged particle beams such as electron beams. Is appropriately selected and used.
Further, the radiation irradiation conditions such as the radiation dose are appropriately selected according to the blending ratio of each component in the resist composition, the kind of the additive, and the like.

When forming a resist pattern using the resist composition of the present invention, a protective film may be provided on the resist film to prevent the influence of basic impurities contained in the working atmosphere. it can. Further, in the present invention, in order to improve the apparent sensitivity of the resist film, it is preferable to perform baking after irradiation with radiation. The heating condition is usually 30 to 200 ° C., preferably 50 to 150 ° C., though it varies depending on the compounding ratio of each component of the resist composition, the kind of additive and the like.

Next, by developing with an alkali developing solution, a predetermined resist pattern is formed. Examples of the alkaline developer include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine,
Triethylamine, methyldiethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, choline, pyrrole, piperidine, 1,8
-Diazabicyclo- [5.4.0] -7-undecene,
An alkaline aqueous solution prepared by dissolving an alkaline compound such as 1,5-diazabicyclo- [4.3.0] -5-nonene to a concentration of usually 1 to 10% by weight, preferably 2 to 5% by weight is used. To be done. Further, an appropriate amount of a water-soluble organic solvent such as methanol or ethanol and a surfactant can be added to the developer. When a developing solution composed of an alkaline aqueous solution is used, it is generally washed with water after development.

[0068]

The present invention will be described in more detail with reference to the following examples and comparative examples, but the present invention is not limited to these examples as long as the gist thereof is not exceeded. In the examples, various characteristics were evaluated as follows.

Mw Tosoh Corp. GPC column (G2000H _XL 2 pieces,
G3000H _XL 1 piece, G4000 _XL 1 piece)
The flow rate was 1.0 ml / min, the eluent was tetrahydrofuran, and the column temperature was 40 ° C. Optimal exposure amount After forming a resist film, a KrF excimer laser (248 nm) irradiation device FPA4500 manufactured by Canon is used to irradiate radiation through a pattern mask at 100 ° C.
After 90 seconds of radiation irradiation, firing was performed. Then 2.
A resist pattern was formed by developing with a developing solution containing a 38 wt% tetramethylammonium hydroxide aqueous solution, rinsing with water, and drying. At this time, a radiation dose capable of forming a 0.4 μm line-and-space pattern (1L1S) as designed was taken as the optimum exposure dose. The unit is mJ / cm ² . Resolution The dimension of the smallest resist pattern resolved when radiation was irradiated with the optimum exposure dose was measured and used as the resolution. Residual film rate The film thickness of the resist pattern obtained by irradiating with the optimal exposure dose by α-step manufactured by Tencor Co. was divided by the film thickness of the resist film before development, and this value was expressed in%. The substrate having the resist pattern after the taper angle development was cut, and the angle between the substrate and the inner side surface of the pattern was measured by an electron microscope to obtain the taper angle. A taper angle of 90 degrees was the best, and a taper angle of more than 90 degrees was considered defective.

Synthesis Example 1 123 g (0.7 mol) of pt-butoxystyrene, 31.2 g (0.3 mol) of styrene, 8.2 g (0.05 mol) of azobisisobutyronitrile and 1 of dodecyl mercaptan. 0.76 g (0.0087 mol) was dissolved in 200 ml of dioxane and reacted under a nitrogen atmosphere for 10 hours while maintaining the internal temperature at 75 ° C. After the reaction, reprecipitation treatment was performed to remove unreacted monomers, and a poly (pt-butoxystyrene-styrene) copolymer resin was obtained. Subsequently, this resin was hydrolyzed with an acid to give poly (p
80 g of (hydroxystyrene-styrene) copolymer resin was obtained. When the copolymerization ratio was determined by NMR, it was p-hydroxystyrene: styrene = 70: 30 (molar ratio). This resin is called resin (A1).

Synthesis Example 2 176 g (1.0 mol) of pt-butoxystyrene, 8.2 g (0.05 mol) of azobisisobutyronitrile and 1.76 g (0.0087 mol) of dodecyl mercaptan were dissolved in 200 ml of dioxane. And was reacted in a nitrogen atmosphere for 10 hours while maintaining the internal temperature at 75 ° C. After the reaction, reprecipitation treatment is performed to remove unreacted monomers, and poly (p
-T-butoxystyrene) resin was obtained. Subsequently, this resin was hydrolyzed with an acid to obtain 72 g of a poly (p-hydroxystyrene) resin having an Mw of 9,000. This resin is referred to as resin (A2).

Examples 1 to 14 and Comparative Examples 1 to 4 Alkali-soluble resins, radiation-sensitive acid generators, crosslinking agents, basic compounds and solvents shown in Table 1 were mixed and dissolved,
The foreign matter was removed by microfiltration with a 0.2 μm filter to obtain a resist composition solution. The obtained resist composition solution was spin-coated on a 4-inch silicon wafer and then baked at 110 ° C. for 2 minutes to form a resist film having a film thickness of 1 μm on the formed resist film through a mask.
Irradiation with rF excimer laser (wavelength 248 nm) was performed.
After that, baking was performed after irradiation with radiation at 100 ° C. for 90 seconds. Next, development was performed by a paddle method at 23 ° C. for 60 seconds with a developing solution, and then rinsed with water for 30 seconds to form a resist pattern. The obtained results are shown in Table 1.

The radiation-sensitive acid generator, the cross-linking agent and the solvent in Tables 1 and 2 are as follows. Radiation-sensitive acid generator (B1): Compound represented by the formula (6) (B2): Compound represented by the formula (7) (B3): Compound represented by the formula (8) (B4): The above Compound represented by formula (9) (B5): Compound represented by formula (10) (B6): Compound represented by formula (11) (B7): Compound represented by formula (4) (B8) : Compound represented by the above formula (5) (B9): Triphenylsulfonium trifluoromethylsulfonate cross - linking agent (C1): Tetramethoxymethylolurea (MX290 Sanwa Chemical Co., Ltd.) (C2): Hexamethoxymethylolmelamine (CYMEL300 Mitsui Cyanamid) Basic compound (D1): tri-n-butylamine solvent (E1): ethyl lactate (2-hydroxypropion) Ethyl acid salt) (E2): Methyl 3-methoxypropionate

[0074]

[Table 1]

[0075]

[Table 2]

[0076]

The radiation-sensitive resin composition of the present invention has a wide tolerance for the radiation dose of the resist film, can form a rectangular pattern with high resolution, and is excellent in sensitivity, developability, resolution and the like. It is suitable as a chemically amplified negative resist. In particular, the radiation-sensitive resin composition of the present invention can effectively suppress the side etching phenomenon and meandering of the resist pattern at the time of development, and can be exposed to both ultraviolet rays such as i-line and far ultraviolet rays such as excimer laser. Furthermore, it can also be used for irradiation of wavelengths of far ultraviolet rays or less, such as X-rays such as synchrotron radiation and charged particle beams such as electron beams, and radiation-sensitive resin composition for semiconductor device manufacturing, which is expected to be further miniaturized in future. It can be suitably used as a product.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Akira Tsuji 2-11-24 Tsukiji, Chuo-ku, Tokyo Japan Synthetic Rubber Co., Ltd.

Claims (1)

[Claims] 1. A) an alkali-soluble resin, B) a radiation-sensitive acid generator comprising at least one selected from a bissulfonyldiazomethane compound and an imidosulfonate compound, C) a cross-linking agent comprising an alkoxymethylated urea compound, and D). A radiation-sensitive resin composition comprising a basic compound composed of trialkylamine.