JPH09325492A - Negative radiation-sensitive resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate scum after development and form a rectangular pattern with high resolution by containing an alkali-soluble copolymer containing specific repetition units and other repetition units and a radiation-sensitive acid generating agent. SOLUTION: An alkali-soluble copolymer containing the repetition unit expressed by the formula I and the repetition unit expressed by the formula II and a radiation-sensitive acid generating agent are contained in this negative radiation-sensitive resin composition. In the formulas, R<1> is hydrogen atom or methyl group, R<2> is hydrogen atom or methyl group, R<3> is alkylene group having 1-4 carbon atoms or alkylidene group having 2-4 carbon atoms, R<4> is alkyl group having 1-4 carbon atoms or halogenated alkyl group having 1-4 carbon atoms, and (n) is a numeral of 0-5. Single or two or more kinds of repetition units may exist in the formula I. The content of the repetition units in the copolymer is preferably set to 30-95mol%, more preferably to 40-90mol%, of the whole repetition units.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a negative radiation-sensitive resin composition. More specifically, it relates to a negative radiation-sensitive resin composition useful as a chemically amplified negative resist suitable for fine processing using radiation such as deep ultraviolet rays, X-rays or charged particle beams.

[0002]

2. Description of the Related Art In the field of microfabrication represented by the manufacture of integrated circuit elements, miniaturization of the processing size in lithography is progressing in order to obtain a higher degree of integration. There is a need for a technique capable of stably performing fine processing. for that reason,
The resist used is also required to be able to form a pattern of 0.30 μm or less with high accuracy, and from this viewpoint, lithography using radiation having a shorter wavelength is being studied. Examples of such short wavelength radiation include deep ultraviolet rays represented by KrF excimer laser (wavelength 248 nm) and ArF excimer laser (wavelength 193 nm), and X represented by synchrotron radiation.
Rays and charged particle rays such as electron rays are used, and in recent years, various resists that can cope with these radiations have been investigated. Among such resists, one that has received special attention is 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. It is called "amplified resist".

By the way, when actually manufacturing an integrated circuit using a resist, a resist solution is usually prepared by dissolving resist components such as a radiation-sensitive component and a film-forming resin component in a solvent to prepare the resist solution. By applying the solution on the substrate to be processed to form a resist film, irradiating the resist film with radiation through a predetermined mask (hereinafter referred to as “exposure”), and developing the resist film. Although a pattern suitable for fine processing is formed, the pattern shape at that time has a significant influence on the precision of fine processing, and a rectangular shape is preferable. A chemically amplified negative resist containing a conventional cross-linking agent and an alkali-soluble resin causes a cross-linking reaction in the exposed area to reduce the dissolution rate in a developing solution to form a pattern. Since the contrast of the dissolution rate between the exposed part and the unexposed part with respect to the liquid is not sufficient, there is a drawback that the resolution is low, and the pattern head shape becomes round instead of rectangular. The decrease in dissolution rate is not sufficient, and the pattern swells with the developer,
There is also a problem of meandering, and further, there is a problem that conventional crosslinking agents have insufficient solubility in a developing solution and scum occurs during development.

[0004]

The object of the present invention is that there is no scum after development, the developability is excellent, a rectangular pattern can be formed with high resolution, and the sensitivity and dimensional fidelity are excellent. It is an object of the present invention to provide a negative radiation-sensitive resin composition suitable as a chemically amplified negative resist. Still other objects and advantages of the present invention will become apparent from the following description.

[0005]

According to the present invention, the above objects and advantages of the present invention are achieved by the following formula (1):

[0006]

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Here, R ¹ is a hydrogen atom or a methyl group, and a repeating unit represented by the following formula (2)

[0008]

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Here, R ² is a hydrogen atom or a methyl group, R ³ is an alkylene group having 1 to 4 carbon atoms or an alkylidene group having 2 to 4 carbon atoms, and R ⁴ is a hydrogen atom or 1 to 1 carbon atoms. Alkali-soluble copolymer (A) containing a repeating unit represented by an alkyl group of 4 or a halogenated alkyl group of 1 to 4 carbon atoms, and n is a number of 0 to 5 (hereinafter , "Copolymer (A)"), and a radiation-sensitive acid generator (B) are contained in the negative radiation-sensitive resin composition. The repeating unit (2) in the present invention is a component for imparting self-crosslinking reactivity to the copolymer, and by containing the repeating unit, in the present invention, a low molecular weight crosslinking agent is added. It is not necessary to use it.

The components constituting the composition of the present invention will be described below in order. Copolymer (A) The copolymer (A) used in the present invention comprises a repeating unit represented by the above formula (1) (hereinafter referred to as “repeating unit (1)”) and a formula (2). It is an alkali-soluble copolymer containing the repeating unit represented (hereinafter, referred to as "repeating unit (2)"). In the present invention, since the repeating unit (1) reacts with the repeating unit (2) due to the acid in the exposed portion, a negative resist pattern is formed. In the formula (1), R ¹ is a hydrogen atom or a methyl group. Examples of the monomer that gives the repeating unit represented by the formula (1) include vinylphenol and isopropenylphenol. Copolymer (A)
In the above, the repeating unit (1) may exist alone or in combination of two or more kinds. The content of the repeating unit (1) in the copolymer (A) is preferably 30 to 95 mol% and more preferably 40 to 90 mol% of all repeating units. If it is less than 30 mol%, the resolution as a resist tends to decrease, while if it exceeds 95 mol%,
Sensitivity tends to decrease.

In the formula (2), R ² is a hydrogen atom or a methyl group, R ³ is an alkylene group having 1 to 4 carbon atoms or an alkylidene group having 2 to 4 carbon atoms, and R ⁴ is a hydrogen atom or carbon atom. Number 1-4 alkyl group, or carbon number 1-
4 is a halogenated alkyl group, and n is a number from 0 to 5. As the alkylene group having 1 to 4 carbon atoms, a methylene group, an ethylene group, a trimethylene group, a methylethylene group,
Examples thereof include a tetramethylene group and a dimethylethylene group. As the alkylidene group having 2 to 4 carbon atoms,
Examples thereof include an ethylidene group, a propylidene group, an isopropylidene group, and a butylidene group. Carbon number 1
The alkyl group of 4 may be linear or branched, and specific examples thereof include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group,
A t-butyl group may be mentioned. Examples of the halogenated alkyl group having 1 to 4 carbon atoms include a trifluoromethyl group, a heptafluoropropyl group and a nonafluorobutyl group.

Examples of the monomer giving the repeating unit represented by the above formula (2) include N-methylolacrylamide, N-methylolmethacrylamide, N-methoxymethylacrylamide, N-methoxymethylmethacrylamide and N-methoxyethoxy. Examples thereof include methyl acrylamide and N-methoxyethoxymethyl methacrylamide. In the copolymer (A), the repeating unit (2) may exist alone or in combination of two or more. The content of the repeating unit (2) in the copolymer (A) is preferably 5 to 70 mol% and more preferably 10 to 50 mol% based on all repeating units. 5 mol%
If less than, the sensitivity as a resist tends to decrease,
On the other hand, if it exceeds 70 mol%, the resolution tends to decrease.

The copolymer (A) may contain, in addition to the repeating unit (1) and the repeating unit (2), another repeating unit (3) different from them. Examples of the other monomer that provides another repeating unit (3) (hereinafter referred to as “repeating unit (3)”) copolymerizable with the monomer that provides the repeating units (1) and (2) include Examples thereof include saturated group-containing compounds, (meth) acrylamide compounds, (meth) acrylic acid esters, and ethylenically unsaturated group-containing carboxylic acids. Examples of the vinyl group-containing compound include unsaturated group-containing aromatic compounds such as styrene, α-methylstyrene, p-methylstyrene, chlorostyrene, acetoxystyrene, t-butoxystyrene, and t-butoxycarbonyloxystyrene.
Examples thereof include hetero atom-containing alicyclic vinyl compounds such as vinylpyrrolidone and vinylcaprolactam, and cyano group-containing vinyl compounds such as acrylonitrile and methacrylonitrile.

As the (meth) acrylamide compound,
For example, acrylamide, methacrylamide, N, N-dimethylacryl (meth) amide, N, N-dimethylaminopropyl (meth) acrylamide and the like can be mentioned. Examples of the (meth) acrylic acid esters include alkyl (meth) acrylates such as methyl (meth) acrylate and ethyl (meth) acrylate, methoxyethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, and 2-hydroxypropyl. (Meth) acrylate, phenyl (meth) acrylate, isobornyl (meth) acrylate, 2-cyanoethyl (meth) acrylate, etc. can be mentioned.

Examples of the ethylenically unsaturated carboxylic acids include itaconic acid, acrylic acid, methacrylic acid,
Fumaric acid, maleic acid, phthalic acid mono (2-acryloyloxyethyl) ester, phthalic acid mono (2-acryloyloxypropyl) ester, succinic acid mono (2-
Examples thereof include acryloyloxyethyl) ester. In the copolymer (A), the repeating unit (3) may be present alone or in combination of two or more. The content of the repeating unit (3) in the copolymer (A) is preferably 0 to 60 mol% and more preferably 5 to 50 mol% based on all repeating units. If it exceeds 60 mol%, the resolution may decrease.

As the method for producing the alkali-soluble resin (A), for example, (a) a monomer having a hydroxyl group of p-vinylphenol protected, such as butoxycarbonyloxystyrene, butoxystyrene, acetoxystyrene, tetrahydropyranyloxystyrene, etc. By addition-polymerizing with a monomer giving the repeating unit of the formula (2) and optionally another copolymerizable monomer giving the repeating unit (3), and then reacting with an acid catalyst, The protecting group is hydrolyzed to give (co) p-vinylphenol.
A method for obtaining a polymer, (b) p-vinylphenol, isopropenylphenol is used as a monomer which gives a repeating unit of the formula (2) and optionally another copolymerizable monomer which gives a repeating unit (3). Examples thereof include a method of addition polymerization with a monomer. The addition polymerization can be carried out by an appropriate method such as radical polymerization, anionic polymerization, cationic polymerization or thermal polymerization. Examples of the acid catalyst include inorganic acids such as hydrochloric acid and sulfuric acid. The weight average molecular weight (hereinafter referred to as Mw) of the alkali-soluble resin (A) is preferably 2,000.
0 to 50,000, more preferably 3,000 to 30,000
00. When the Mw is less than 2,000, the film-forming property, the sensitivity as a resist and the like are deteriorated, while when it exceeds 50,000, the developability and the resolution as a resist are deteriorated.

(B) Radiation-sensitive acid generator The radiation-sensitive acid generator (hereinafter referred to as “acid generator”) is a compound that generates an acid upon exposure. Examples of the acid generator used in the present invention include halogen-containing compounds, onium salts, sulfone compounds, sulfonate compounds, sulfonimide compounds, diazomethane compounds and the like. Examples of these acid generators are shown below. Halogen-containing compound: As the halogen-containing compound,
For example, a haloalkyl group-containing hydrocarbon compound and a haloalkyl group-containing heterocyclic compound are preferably used. Specific examples of the halogen-containing compound include tris (2,3-
Dibromopropyl) isocyanurate, α, α, α-tribromomethylphenyl sulfone, tribromoneopentyl alcohol, 2,2-bis (bromomethyl) -1,3-
Propanediol, pentaerythritol tetrabromide, 2- (bromomethyl) 2- (hydroxymethyl)
-1,3-propanediol, hexabromohexane,
Hexabromoheptane, hexabromocyclododecane,
Bromine compounds such as tetrabromo-o-cresol, tetrabromobisphenol A bishydroxyethyl ether, 2,4-dibromo-2,4-dimethyl-3-pentanone; pentaerythritol tetrachloride, phenyl-bis (trichloromethyl) -s- (Trichloromethyl) -s-triazine derivatives such as triazine, methoxyphenyl-bis (trichloromethyl) -s-triazine and naphthyl-bis (trichloromethyl) -s-triazine, and 1,1-bis (4-chlorophenyl)- 2, 2, 2
-Chlorine compounds such as trichloroethane; iodine compounds such as hexaiodohexane and p-diiodobenzene.

Onium salts: Examples of onium salts include iodonium salts, sulfonium salts, phosphonium salts,
Examples thereof include diazonium salts, ammonium salts, and pyridinium salts. Specific examples of the onium salt compound include diphenyliodonium triflate, diphenyliodonium pyrene sulfonate, diphenyliodonium dodecylbenzenesulfonate, triphenylsulfonium triflate, triphenylsulfonium hexafluoroantimonate, diphenyliodonium hexafluoroantimonate, and triphenylsulfonium naphthalene. Sulfonate, triphenylsulfonium camphorsulfonate, (hydroxyphenyl) benzylmethylsulfonium toluenesulfonate and the like can be mentioned. Sulfone compound: Examples of the sulfone compound include β
-Ketosulfone, β-sulfonylsulfone, their α
-A diazo compound etc. can be mentioned. Specific examples of the sulfone compound include phenacylphenyl sulfone,
Mesitylphenacyl sulfone, bis (phenylsulfonyl) methane, 4-trisphenacyl sulfone and the like can be mentioned.

Sulfonic acid ester compound: Examples of the sulfonic acid ester compound include alkyl sulfonic acid ester, haloalkyl sulfonic acid ester, aryl sulfonic acid ester, imino sulfonate and the like. Specific examples of the sulfonic acid ester compound include benzoin tosylate, pyrogallol tris triflate, pyrogallol methanesulfonic acid triester,
Nitrobenzyl-9,10-diethoxyanthracene-
Examples thereof include 2-sulfonate, α-methylol benzoin tosylate, α-methylol benzoin octane sulfonate, α-methylol benzoin trifluoromethane sulfonate, α-methylol benzoindodecyl sulfonate. Sulfonimide compound: As the sulfonimide compound, for example, the following formula (3)

[0020]

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Here, X ¹ represents a divalent group such as an alkylene group, an arylene group or an alkoxylene group, and R ₅ represents a monovalent group such as an alkyl group, an aryl group, a halogen-substituted alkyl group or a halogen-substituted aryl group. A compound represented by a group can be mentioned.

Specific examples of the sulfonimide compound include:
N- (trifluoromethylsulfonyloxy) succinimide, N- (trifluoromethylsulfonyloxy)
Phthalimide, N- (trifluoromethylsulfonyloxy) diphenylmaleimide, N- (trifluoromethylsulfonyloxy) bicyclo [2.2.1] hept-5
-Ene-2,3-dicarboximide, N- (trifluoromethylsulfonyloxy) -7-oxabicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (tri Fluoromethylsulfonyloxy)
Naphthylimide, N- (trifluoromethylsulfonyloxy) bicyclo [2.2.1] heptane-5,6-oxy-2,3-dicarboximide, N- (camphorsulfonyloxy) succinimide, N- (camphorsulfonyl) Oxy) phthalimide, N- (camphorsulfonyloxy) diphenylmaleimide, N- (camphorsulfonyloxy) bicyclo [2.2.1] hept-5
-Ene-2,3-dicarboximide, N- (camphorsulfonyloxy) -7-oxabicyclo [2.2.
1] hept-5-ene-2,3-dicarboximide,
N- (camphorsulfonyloxy) naphthylimide,
N- (camphorsulfonyloxy) bicyclo [2.2.
1] heptane-5,6-oxy-2,3-dicarboximide,

N- (4-methylphenylsulfonyloxy) succinimide, N- (camphorsulfonyloxy) naphthyldicarboximide, N- (4-methylphenylsulfonyloxy) phthalimide, N- (4-methylphenylsulfonyloxy) diphenyl Maleimide, N- (4-methylphenylsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (4-methylphenylsulfonyloxy) -7-oxabicyclo [ 2.2.1] Hept-5-ene-2,3-dicarboximide, N- (4-methylphenylsulfonyloxy) naphthylimide, N- (4-
Methylphenylsulfonyloxy) bicyclo [2.2.
1] Heptane-5,6-oxy-2,3-dicarboximide, N- (2-trifluoromethylphenylsulfonyloxy) succinimide, N- (2-trifluoromethylphenylsulfonyloxy) phthalimide, N-
(2-trifluoromethylphenylsulfonyloxy)
Diphenylmaleimide, N- (2-trifluoromethylphenylsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (2
-Trifluoromethylphenylsulfonyloxy) -7
-Oxabicyclo [2.2.1] hept-5-ene-2,
3-dicarboximide, N- (2-trifluoromethylphenylsulfonyloxy) naphthylimide, N-
(2-trifluoromethylphenylsulfonyloxy)
Bicyclo [2.2.1] heptane-5,6-oxy-2,3
-Dicarboximide, N- (2-trifluoromethylphenylsulfonyloxy) naphthylimide, N- (4
-Fluorophenylsulfonyloxy) succinimide, N- (2-fluorophenyl) phthalimide, N-
(4-fluorophenylsulfonyloxy) diphenylmaleimide, N- (4-fluorophenylsulfonyloxy) bicyclo [2.1.1] hept-5-ene-2,3
-Dicarboximide, N- (trifluoromethylsulfonyloxy) -7-oxabicyclo [2.1.1] hept-5-ene-2,3-dicarboximide, N- (4
-Fluorophenylsulfonyloxy) bicyclo [2.
1.1] Heptane-5,6-oxy-2,3-dicarboximide, N- (4-fluorophenylsulfonyloxy) naphthyldicarboximide and the like.

Diazomethane compound: Examples of the diazomethane compound include those represented by the following formula (4)

[0025]

[Chemical 6]

Here, R ₆ and R _{7, which} may be the same or different, each represents a monovalent group such as an alkyl group, an aryl group, a halogen-substituted alkyl group or a halogen-substituted aryl group. Can be mentioned.

Specific examples of the diazomethane compound include bis (trifluoromethylsulfonyl) diazomethane, bis (cyclohexylsulfonyl) diazomethane, bis (phenylsulfonyl) diazomethane, bis (p-toluenesulfonyl) diazomethane, methylsulfonyl-p.
-Toluenesulfonyldiazomethane, 1-cyclohexylsulfonyl-1- (1,1-dimethylethylsulfonyl) diazomethane, bis (1,1-dimethylethylsulfonyl) diazomethane and the like. Of the acid generators, halogen-containing compounds, onium salts, sulfonimide compounds and diazomethane compounds are preferred.

These acid generators may be used alone or in combination of two or more. The amount of the acid generator compounded is usually 0.1 per 100 parts by weight of the alkali-soluble resin.
The amount is 01 to 20 parts by weight, preferably 0.1 to 12 parts by weight, and more preferably 2 to 10 parts by weight. In this case, if the blending amount of the acid generator is outside the above range, the pattern shape tends to deteriorate.

Acid Diffusion Control Agent In the composition of the present invention, the action of controlling the diffusion phenomenon of the acid generated from the acid generator by exposure in the resist film and suppressing the undesired chemical reaction in the unexposed area, etc. It is more preferable to use an acid diffusion control agent having By using such an acid diffusion control agent,
The storage stability of the composition of the present invention is improved, the resolution as a resist is improved, and the change in the line width of the resist pattern due to the variation of PED can be suppressed, resulting in extremely excellent process stability. As such an acid diffusion control agent, a nitrogen-containing organic compound whose basicity does not change by exposure or heating is preferable, and as such a nitrogen-containing organic compound, for example, a compound represented by the following formula (3) (hereinafter, "containing nitrogen compound (I) "hereinafter) indicates the ^{R 5 R 6 R 7 N ···} (3) ( wherein R ^5, R ^6, R ⁷ each independently represent a hydrogen atom, an alkyl group, an aryl group or an aralkyl group ) A diamino compound having two or more nitrogen atoms in the same molecule (hereinafter referred to as "nitrogen-containing compound (II)"), a polyamino polymer having three or more nitrogen atoms (hereinafter referred to as "nitrogen-containing compound (III)") ), An amide group-containing compound, a urea compound, and a nitrogen-containing heterocyclic compound.

Examples of the nitrogen-containing compound (I) include n-
Monoalkylamines such as hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine; di-n-butylamine, di-n-pentylamine, di-n-hexylamine, di-n -Dialkylamines such as heptylamine, di-n-octylamine, di-n-nonylamine, di-n-decylamine; triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, Tri-n-hexylamine, tri-n-heptylamine,
Tri-n-octylamine, tri-n-nonylamine,
Trialkylamines such as tri-n-decylamine;
Aniline, N-methylaniline, N, N-dimethylaniline, 2-methylaniline, 3-methylaniline, 4-
Aromatic amines such as methylaniline, 4-nitroaniline, naphthylamine, diphenylamine and triphenylamine can be mentioned.

Examples of the nitrogen-containing compound (II) include ethylenediamine, N, N, N ', N'-tetramethylethylenediamine, tetramethylenediamine, hexamethylenediamine, 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 and the like can be mentioned.

Examples of the nitrogen-containing compound (III) include polyethyleneimine, polyallylamine, a polymer of dimethylaminoethyl acrylamide, a polymer of dimethylaminoethyl methacrylate, and the like.
Examples of the amide group-containing compound include formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N,
Examples thereof include N-dimethylacetamide, propionamide, benzamide, pyrrolidone and N-methylpyrrolidone.

Examples of the above urea compound include urea,
Methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-
Examples thereof include diphenylurea and tributylurea. Examples of the nitrogen-containing heterocyclic compound include imidazoles such as imidazole, benzimidazole, 4-methylimidazole, 4-methyl-2-phenylimidazole, pyridine, 2-methylpyridine, 4-methylpyridine, 2-ethylpyridine, and the like. 4-ethylpyridine, 2-phenylpyridine, 4-phenylpyridine, N
Pyridines such as -methyl-4-phenylpyridine, nicotine, nicotinic acid, nicotinamide, quinoline, 8-oxyquinoline and acridine;
Pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidine, morpholine, 4-methylmorpholine, piperazine, 1,4-dimethylpiperazine, 1,4-
Examples thereof include diazabicyclo [2.2.2] octane. Among these nitrogen-containing organic compounds, the nitrogen-containing compound (I) and the nitrogen-containing heterocyclic compound are preferable. These acid diffusion control agents can be used alone or in combination of two or more.

The mixing ratio of the acid diffusion inhibitor in the present invention is usually 0.01 to 100 parts by weight of the copolymer (A).
It is 10 parts by weight, preferably 0.05 to 5 parts by weight. In this case, if the amount of the acid diffusion controller used is less than 0.01 part by weight, the pattern shape and dimensional fidelity as a resist may be reduced depending on the process conditions.
If the amount exceeds the weight part, the sensitivity as a resist and the developability of the exposed part tend to decrease.

Other Alkali-Soluble Resin In the present invention, an alkali-soluble resin other than the copolymer (A) (hereinafter referred to as "other alkali-soluble resin") can be added, if necessary. The other alkali-soluble resin is a resin soluble in an alkali developing solution, which has at least one functional group having an affinity with the alkali developing solution, for example, an acidic functional group such as phenolic hydroxyl group, carboxyl group, sulfonic acid and phosphoric acid. Is. By using such an alkali-soluble resin, it becomes easier to control the dissolution rate of the resist coating film in the alkali developer with the composition of the present invention, so that the developability can be further improved.

The other alkali-soluble resin is not particularly limited as long as it is soluble in the alkali developing solution, but preferable other alkali-soluble resin is, for example, hydroxystyrene, isopropenylphenol,
Vinylbenzoic acid, carboxymethylstyrene, carboxymethoxystyrene, (meth) acrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, cinnamic acid, methallylsulfonic acid, p-vinylphenylsulfonic acid Containing an addition polymerization type resin containing a repeating unit in which the polymerizable double bond portion of at least one monomer having an acidic functional group such as is cleaved, or a condensation type repeating unit having an acidic functional group represented by novolak resin Examples thereof include polycondensation resins. Other alkali-soluble resin consisting of the addition polymerization resin, the polymerizable double bond portion of the monomer having an acidic functional group may be composed only of repeating units cleaved,
As long as the resin produced is soluble in the alkaline developer,
It may also contain one or more other repeating units.

Examples of such other repeating units include styrene, t-butoxystyrene, t-butoxycarbonyloxystyrene, α-methylstyrene, vinyltoluene, maleic anhydride, (meth) acrylonitrile,
Croton nitrile, malein nitrile, fumaro nitrile, mesacon nitrile, citracon nitrile, itacone nitrile, (meth) acrylamide, crotonamide,
Repeated cleavage of the polymerizable double bond portion of monomers such as maleamide, fumaramide, mesacone amide, citraconamide, itacone amide, vinylaniline, vinylpyridine, N-vinyl-ε-caprolactam, N-vinylpyrrolidone, N-vinylimidazole. Units can be mentioned.

Among the above addition-polymerization resins, polyvinylphenol, vinylphenol-styrene copolymer and isopropenylphenol copolymer are particularly preferable from the viewpoints of high radiation permeability when used as a resist film and excellent dry etching resistance. Polymers and the like are preferable. Further, the other alkali-soluble resin consisting of the polycondensation resin may be composed only of polycondensation repeating units having an acidic functional group, as long as the produced resin is soluble in an alkali developing solution. , And may further contain other repeating units. Such a polycondensation resin is, for example, 1
One or more phenols and one or more aldehydes,
Producing by (co) polycondensation in an aqueous medium or in a mixed medium of water and a hydrophilic solvent in the presence of an acidic catalyst, optionally together with a polycondensation component capable of forming another polycondensation repeating unit. You can

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,
Examples thereof include 2,3,5-trimethylphenol, 3,4,5-trimethylphenol, and the aldehydes include, for example, formaldehyde, trioxane, paraformaldehyde, benzaldehyde, acetaldehyde, propylaldehyde, phenylacetaldehyde, etc. Can be mentioned. The amount of the other alkali-soluble resin used in the present invention is the same as that of the copolymer (A) 1
It is usually 200 parts by weight or less per 00 parts by weight.

Dissolution enhancer In the present invention, a dissolution enhancer can be added as necessary. When the solubility of the copolymer (A) in the alkali developing solution is too low, the dissolution accelerator enhances the solubility thereof to appropriately increase the dissolution rate of the copolymer (A) during alkali development. It is a compound that has. As such a dissolution accelerator, those which do not chemically change in the steps of baking the resist film, irradiating with radiation and developing are preferable. Examples of such a dissolution accelerator include low molecular weight phenolic compounds having about 2 to 6 benzene rings, and specific examples include bisphenols and tris (hydroxyphenyl) methane. be able to. The content of the dissolution accelerator is appropriately adjusted depending on the type of the copolymer (A) used, but is usually 50 parts by weight or less, preferably 30 parts by weight, per 100 parts by weight of the copolymer (A). It is the following.

The sensitizer in the compositions of the present invention may be added a sensitizer.
This 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, and is formed by the composition of the present invention. It has the effect of improving the apparent sensitivity of the resist. Examples of preferable sensitizers include acetophenones, benzophenones, pyrenes and anthracenes. These sensitizers are
These may be used alone or in combination of two or more, and the amount thereof is usually 50 parts by weight or less, preferably 30 parts by weight or less, per 100 parts by weight of the copolymer (A) in the composition.

[0042] Compositions of the surfactant present invention may contain a surfactant. Examples of this surfactant include commercially available products such as F-top EF301, EF303, EF352 (manufactured by Tochem Products), Megafax F171, F17.
3 (manufactured by Dainippon Ink and Chemicals, Inc.), Florard FC430,
FC431 (Sumitomo 3M Limited), Asahi Guard AG710, Surflon S-382, SC101, SC
102, SC103, SC104, SC105, SC1
06 (manufactured by Asahi Glass Co., Ltd.), organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), polyflow N which is an acrylic acid-based or methacrylic acid-based (co) polymer.
No. 75, No. 95 (trade name, manufactured by Kyoeisha Oil and Fat Chemical Co., Ltd.) and the like are used. The blending amount of surfactant is
It is usually 2 parts by weight or less per 100 parts by weight of the copolymer (A).

Crosslinking Agent A compound capable of crosslinking the repeating unit (1) in the copolymer (A) can be added to the composition of the present invention as a crosslinking agent. Examples of such compounds include alkoxymethylated urea resins, alkoxymethylated melamine resins, alkoxymethylated urone resins, alkoxymethylated glycoluril resins and other alkoxymethylated amino resins. The blending amount of these crosslinking agents is 50 parts by weight or less per 100 parts by weight of the copolymer (A). Solvent The composition of the present invention, when used, has a total solid content of, for example, 5 to 50% by weight, preferably 15 to 40% by weight, after being uniformly dissolved in a solvent, for example, a pore size of 0. By filtering with a filter of about 2 μm,
Prepared as a composition solution.

Examples of the solvent used for preparing the composition solution include 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 ethers. Acetates; Propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate and other propylene glycol monoalkyl ether acetates; methyl lactate, ethyl lactate, n-propyl lactate, lactic acid Lactic acid esters such as isopropyl; methyl acetate, Ethyl acetate n- propyl, isopropyl acetate, n- butyl, aliphatic carboxylic acid esters such as isobutyl acetate;

Ethyl 2-hydroxy-2-methylpropionate, methyl 2-hydroxy-3-methylbutyrate, ethyl methoxyacetate, ethyl ethoxyacetate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate,
Other esters such as methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, methyl pyruvate and ethyl pyruvate; aromatic hydrocarbons such as toluene and xylene; methyl ethyl ketone, methyl propyl ketone, methyl butyl ketone, 2 -Keptanes such as heptanone, 3-heptanone, 4-heptanone and cyclohexanone; amides such as N-methylformamide, N, N-dimethylformamide and N-methylpyrrolidone; lactones such as γ-butyrolacun . These solvents can be used alone or in combination of two or more.

Formation of Resist Pattern When forming a resist pattern from the composition of the present invention, the composition solution prepared as described above is applied by a suitable coating means such as spin coating, cast coating or roll coating. By coating on a substrate such as a silicon wafer or a wafer covered with aluminum to form a resist film, and in some cases, heat treatment in advance (hereinafter,
It is called "prebaking". ) Is performed, and then exposure is performed through a predetermined mask pattern. At that time, as radiation,
Depending on the type of acid generator, for example, i-line (wavelength 365n
m) ultraviolet light; ArF excimer laser (wavelength 19
3 nm), KrF excimer laser (wavelength 248 nm)
Far ultraviolet rays such as; X-rays such as synchrotron radiation; charged particle beams such as electron beams are appropriately selected and used. Of these, deep ultraviolet rays are preferably used.

The composition of the present invention is preferably subjected to a heat treatment after exposure (hereinafter referred to as "post-exposure bake") in order to improve the apparent sensitivity as a resist film. The heating conditions can be changed depending on the composition of the composition of the present invention, the type of each additive, etc., but are usually 30 to 200.
° C, preferably 40 to 150 ° C. Next, a predetermined resist pattern is formed by subjecting the exposed resist film to alkali development with an alkali developer.

Examples of the alkaline developer include mono-, di- or tri-alkylamines; mono-, di- or tri-alkanolamines; heterocyclic amines; tetraalkylammonium hydroxides; choline; Alkaline compounds such as 1,8-diazabicyclo [5.4.0] -7-undecene and 1,5-diazabicyclo [4.3.0] -5-nonene are usually added in an amount of 1 to 10% by weight,
It is preferable to use an alkaline aqueous solution which is dissolved to have a concentration of 1 to 5% by weight. These alkaline compounds can be used alone or in combination of two or more.

Further, a water-soluble organic solvent such as methanol or ethanol, or a surfactant may be appropriately added to the developer containing the alkaline aqueous solution. When a developer composed of an alkaline aqueous solution is used, washing is generally performed after development. In forming the resist pattern, a protective film may be provided on the resist film in order to prevent the influence of basic impurities contained in the ambient atmosphere.

[0050]

EXAMPLES The embodiments of the present invention will be described below with reference to examples. However, the present invention is not limited to these embodiments at all unless it exceeds the gist. Each measurement / evaluation in Examples and Comparative Examples was carried out by the following methods.

A high-speed GPC device HLC-8020 manufactured by Mw Tosoh Corp. was added to a GPC column (G2000H _XL : 2 columns, G3, manufactured by Tosoh Corp.).
000H _XL : 1 bottle, G4000H _XL : 1 bottle), using a flow rate of 1.0 ml / min, an elution solvent of tetrahydrofuran, and a column temperature of 40 ° C. under the analysis conditions of a gel permeation chromatography method using monodisperse polystyrene as a standard. It was measured. The measurement sample was a 1% THF solution.

The optimum exposure amount was defined as the exposure amount capable of forming a line-and-space pattern (1L1S) having a sensitivity line width of 0.3 μm as designed, and the sensitivity was evaluated by this optimum exposure amount.

Resolution (μm) The dimension of the smallest resist pattern resolved when exposed at the optimum exposure dose was measured and defined as the resolution. 1L1 with a line width of 0.3μm formed on a developable silicon wafer
Observe the square cross section of S using a scanning electron microscope,
Evaluation was made according to the following criteria. ◯: No development residue is observed between patterns. Δ: Some development residue is observed between the patterns. X: There is a large amount of development residue between patterns.

1L1 with a line width of 0.3 μm formed on a patterned silicon wafer
A pattern in which the lower side dimension La and the upper side dimension Lb of the S-shaped cross section are measured using a scanning electron microscope to satisfy 0.85 ≦ Lb / La ≦ 1 and the pattern upper layer is not round. The shape was evaluated as "rectangular" according to the following criteria. ◯: The pattern shape is rectangular. Δ: The head of the pattern is round, and swelling is recognized in part. X: The pattern swells significantly and meanders, or the pattern cannot be formed.

Synthesis of Alkali-Soluble Copolymer (A) Synthesis Example 1 45 g of p-acetoxystyrene and 5 g of N-methylolacrylamide were mixed with 200 g of dioxane to obtain a uniform solution. After bubbling this solution for 30 minutes,
6 g of 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile) was added, and while continuing the bubbling with nitrogen gas, the reaction temperature was maintained at 60 ° C. for copolymerization for 7 hours. After completion of the polymerization, the reaction solution was mixed with a large amount of hexane to coagulate the produced copolymer. Next, after redissolving the copolymer in dioxane, the operation of solidifying again with hexane was repeated several times to completely remove the unreacted monomer, and dried under reduced pressure at 50 ° C. to obtain a white copolymer. Got The obtained copolymer was dissolved in 500 g of propylene glycol monomethyl ether, 50 g of a 25% aqueous ammonia solution was added, and the mixture was stirred at 60 ° C. for 5 hours for hydrolysis. Then, the reaction solution was poured into a 0.1% oxalic acid aqueous solution to solidify the copolymer. The obtained copolymer was washed with water and dried under reduced pressure at 50 ° C. to obtain a white copolymer. The obtained copolymer had Mw of 12,000, and as a result of elemental analysis, the copolymerization molar ratio of p-vinylphenol and N-methylolacrylamide was 87:13 in this order. This copolymer is referred to as Polymer A-1
And

Synthesis Example 2 27 g of p-isopropenylphenol, 9 g of N-methoxymethylacrylamide and 14 g of 2-hydroxyethyl acrylate were mixed with 50 g of dioxane to prepare a uniform solution. After bubbling this solution for 30 minutes,
6 g of 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile) was added, and while continuing the bubbling with nitrogen gas, the reaction temperature was maintained at 60 ° C. for copolymerization for 7 hours. After completion of the polymerization, the reaction solution was mixed with a large amount of hexane to coagulate the produced copolymer. Then, after redissolving the copolymer in dioxane, the operation of coagulating again with hexane was repeated several times to completely remove the unreacted monomer, and dried under reduced pressure at 50 ° C. to obtain a white copolymer. Got The copolymer obtained has an Mw of 9,000.
As a result of H-NMR measurement, the copolymerization molar ratio with p-isopropenylphenol, N-methoxymethylacrylamide and 2-hydroxyethyl acrylate was 48:20:32 in this order. This copolymer is referred to as a polymer A-2.

Synthetic Example 3 27 g of p-isopropenylphenol, 5 g of N-methoxymethylacrylamide, 10 g of 2-hydroxyethyl acrylate and 8 g of styrene were mixed with 50 g of dioxane to obtain a uniform solution. After bubbling this solution for 30 minutes, 2,2'-azobis (4-methoxy-2,4
-Dimethylvaleronitrile) 6 g was added, and while continuing the bubbling with nitrogen gas, the reaction temperature was maintained at 60 ° C. for copolymerization for 7 hours. After completion of the polymerization, the reaction solution was mixed with a large amount of hexane to coagulate the produced copolymer. Then, after redissolving the copolymer in dioxane,
The operation of coagulating again with hexane was repeated several times to completely remove the unreacted monomer, followed by drying under reduced pressure at 50 ° C. to obtain a white copolymer. The obtained copolymer is
Mw is 9,000, and as a result of H-NMR measurement, p-
The molar ratio of copolymerization with isopropenylphenol, N-methoxymethylacrylamide, 2-hydroxyethyl acrylate and styrene was 48: 10: 1 in this order.
It was 8:24. This copolymer is referred to as a polymer A-3.

Synthesis Example 4 20% by weight of p-hydroxystyrene, 65% by weight of p-ethylphenol, and 15% by weight of other components contained as impurities (breakdown: 10% by weight of water, p-cresol 4)
Wt%, 1 wt% phenol) 120g of a mixture of the composition
Was mixed with 23 g of N-methoxymethylacrylamide and 50 g of dioxane to obtain a uniform solution. After bubbling this solution for 30 minutes, 2,2'-azobis (4-
Methoxy-2,4-dimethylvaleronitrile) (1.9 g) was added, and while continuing the bubbling with nitrogen gas, the reaction temperature was maintained at 40 ° C. for copolymerization for 7 hours. After completion of the polymerization, the reaction solution was mixed with a large amount of hexane to coagulate the produced copolymer. Then, the copolymer was redissolved in dioxane and coagulated again with hexane several times to completely remove the unreacted monomer.
Dry under reduced pressure at 0 ° C to give a white copolymer (yield 52%)
I got The obtained copolymer had Mw of 7,000, and as a result of H-NMR measurement, the copolymerization molar ratio of p-hydroxystyrene and N-methoxymethylacrylamide was 51:49 in this order. It was This copolymer is referred to as a polymer A-4.

Examples 1 to 9 and Comparative Example 1 A copolymer (A) shown in Table 1, an alkali-soluble resin, an acid generator, a cross-linking agent, an acid diffusion controller and a solvent were mixed and a filter having a pore size of 0.2 μm was mixed. To remove foreign matter by microfiltration with
A resist solution was prepared. Each obtained resist solution,
After spin coating on a silicon wafer having a diameter of 4 inches, baking is performed at 120 ° C. to form a resist film having a film thickness of 0.7 μm, and a KrF excimer laser (wavelength 248 μm) is applied to the resist film through a pattern mask. Nikon Excimer Stepper (trade name NSR2005EX
8A), irradiation was performed, and then post-exposure baking was performed at 110 ° C. for 1 minute. Then, 2.38% by the paddle method
Alkaline development was performed at 23 ° C. for 60 seconds, followed by washing with water for 30 seconds and drying to form a negative resist pattern. Table 2 shows the evaluation results of the obtained resist patterns.

[0060]

[Table 1]

[0061]

[Table 2]

Each component in the table is as follows. Alkali-soluble resin B-1: poly (p-hydroxystyrene) Mw = 6,
000 B-2: Poly (p-hydroxystyrene) Mw = 1
2,000 B-3: p-hydroxystyrene / styrene copolymer (copolymerization molar ratio = 90/10) Mw = 6,000 acid generator C-1: tris (2,3-dibromopropyl) isocyanurate C -2: triphenylsulfonium triflate C-3: N- (trifluoromethylsulfonyloxy)
Bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide

Crosslinking agent D-1: N, N'-dimethoxymethylurea D-2: N, N'-dimethylolurea acid diffusion controller E-1: tri-n-butylamine E-2: nicotinic acid amide solvent F-1: Ethyl lactate (ethyl 2-hydroxypropionate) F-2: Ethyl ethoxypropionate F-3: 2-Heptanone

[0064]

The negative type radiation-sensitive resin composition of the present invention can form a rectangular resist pattern with high resolution as a chemically amplified negative type resist,
It has excellent developability and dimensional fidelity, and is capable of handling far-ultraviolet rays such as excimer lasers, X-rays such as synchrotron radiation, and short-wave radiation below deep-ultraviolet rays such as charged particle beams such as electron beams. However, it is extremely useful for manufacturing semiconductor devices, which are expected to be further miniaturized in the future.

 ──────────────────────────────────────────────────続 き Continued on front page (72) Inventor Takayoshi Tanabe 2--11-24 Tsukiji, Chuo-ku, Tokyo Inside Nippon Gosei Rubber Co., Ltd.

Claims (1)

[Claims] 1. The following formula (1): Here, R ¹ is a hydrogen atom or a methyl group, and a repeating unit represented by the following formula (2): Here, R ² is a hydrogen atom or a methyl group, R ³ is an alkylene group having 1 to 4 carbon atoms or an alkylidene group having 2 to 4 carbon atoms, and R ⁴ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Group or a halogenated alkyl group having 1 to 4 carbon atoms, and n is a number from 0 to 5, and an alkali-soluble copolymer (A) containing a repeating unit represented by: A negative radiation-sensitive resin composition comprising an acid generator (B).