JPH05107763A - Radiation sensitive resin composition - Google Patents

Abstract

PURPOSE:To improve the developability, pattern shape, heat resistance, film retentivity and resolution of a radiation sensitive resin compsn. and to make this compsn. suitable for use as a resist by incorporating a polymer having specified repeating units and a radiation sensitive agent. CONSTITUTION:A polymer hating repeating units represented by the formula and a radiation sensitive agent are incorporated. In the formula, R<1> is H or methyl, R<2> is H, alkyl, aralkyl, aryl or halogen, each of R<3> and R<4> is H, alkyl, aralkyl, aryl or halogen, (m) us 0, 1, 2 or 3, (n) is 1, 2 or 3 and m+n<4. A compd. which generates an acid under irradiation or a compd. which is decomposed by irradiation and crosslinks the polymer is preferably used as the radiation sensitive agent. The photo-acid initiator is, e.g., an onium salt, a halogen-contg. compd. or a diazoketone compd.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a radiation-sensitive resin composition. More specifically, a radiation-sensitive resin composition suitable as a resist for forming highly integrated circuits, which is particularly sensitive to ultraviolet rays such as i-rays, far ultraviolet rays such as excimer lasers, X-rays such as synchrotron radiation, and charged particle rays such as electron beams Regarding things.

[0002]

2. Description of the Related Art Positive resists are widely used in today's integrated circuit manufacturing because a resist pattern of high resolution can be obtained. However, with the high integration of integrated circuits in recent years, there has been a demand for the formation of resist patterns with higher resolution. One of the means for improving the resolution is a method of shortening the wavelength of radiation used for irradiation, for example, the use of deep ultraviolet rays.

Since a conventional positive resist has a large absorption in deep ultraviolet rays, irradiation with deep ultraviolet rays causes a reduction in resolution, a decrease in sensitivity, a deterioration in resist pattern shape, a deterioration in developability, and the like. It is difficult to use, and a resist suitable for deep ultraviolet rays, especially KrF excimer laser light is desired.

Further, as the degree of integration of integrated circuits is improved, the conventional etching method for wafers is changed from wet etching, which has a large side etching, to dry etching, which has a small side etching. In this dry etching, it is necessary that the resist pattern does not change due to heat during etching, so the resist is required to have heat resistance.

[0005]

An object of the present invention is to provide a radiation sensitive resin composition. Another object of the present invention is a radiation-sensitive resin composition suitable as a resist having excellent developability, pattern shape, resolution, heat resistance and residual film property, and is preferably used for irradiation with radiation having a wavelength of deep ultraviolet rays or less. Another object is to provide a radiation-sensitive resin composition.
Still other objects and advantages of the present invention will be apparent from the following description.

[0006]

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

[0007]

[Chemical 2]

A radiation-sensitive resin composition comprising a polymer having a repeating unit represented by and a radiation-sensitive agent.

The polymer used in the present invention (hereinafter referred to as "polymer (A)") has a repeating unit represented by the above formula (1).

In the above formula (1), the alkyl group represented by R ² may be linear or branched and is preferably one having 1 to 4 carbon atoms. Preferred examples of such an alkyl group include a methyl group, an ethyl group, a t-butyl group, and the like.

The aralkyl group of R ² is preferably an aralkyl group having an alkyl moiety having 1 to 3 carbon atoms, and preferable examples thereof include a benzyl group, a phenethyl group and a 1-methyl-1-phenylethyl group. be able to.

Preferable examples of the aryl group of R ² include a phenyl group and a naphthyl group.
Further, examples of the halogen atom of R ² include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like.

In the above formula (1), as the alkyl group, aralkyl group, aryl group or halogen atom of R ³ and R ⁴ , those similar to those exemplified for R ² can be exemplified as preferable ones. ..

The polymer (A) in the present invention has the formula (1)
It may be composed of only the repeating unit represented by or may have other repeating units. Here, other repeating units include, for example, the following formula (2)

[0015]

[Chemical 3]

The repeating unit represented by can be mentioned as a preferable one.

In the above formula (2), specific examples of the alkyl group, aralkyl group, aryl group or halogen atom of R ⁶ are the same as those exemplified for R ^{2 in the} above formula (1). it can.

As other repeating units, in addition to the repeating unit represented by the above formula (2), for example, acrylic acid, methyl acrylate, ethyl acrylate, glycidyl acrylate, propyl acrylate, methoxyvinyl, t
-Butoxyvinyl, styrene, α-methylstyrene, p
-Repeating units corresponding to a structure in which a double bond of a monomer having a double bond such as methylstyrene, chloromethylstyrene, maleic anhydride, vinyl acetate, vinylpyridine, vinylpyrrolidone or acrylonitrile is cleaved are also preferred. You can

The molecular weight of the polymer (A) in the present invention is
Polystyrene-equivalent weight average molecular weight measured by gel permeation chromatography (hereinafter referred to as "Mw")
Is preferably 10,000 or more and 300,000 or less, more preferably 20,000 or more and 150,000 or less. If the Mw is less than 10,000, the heat resistance tends to decrease, and if it exceeds 300,000, the viscosity of the solution prepared is too high, and it becomes difficult to suitably apply it.

The repeating unit represented by the above formula (1) in the polymer (A) of the present invention has, for example, the following formula (3):

[0021]

[Chemical 4]

Hydroxystyrenes represented by the following formula (4)

[0023]

[Chemical 5]

The compound represented by the formula (hereinafter referred to as "compound (a)") can be obtained by polymerizing the compound obtained by subjecting the compound to aromatic substitution reaction in the presence of an acidic catalyst or in the absence of a catalyst. It can also be obtained by preparing a styrene polymer in advance and reacting it with the “compound (a)” in the same manner as above.

Examples of the hydroxystyrenes include o-hydroxystyrene, m-hydroxystyrene,
p-hydroxystyrene, 3-chloro-4-hydroxystyrene, 3-bromo-4-hydroxystyrene, 4-
Chloro-3-hydroxystyrene, 4-bromo-3-hydroxystyrene, 3-ethyl-4-hydroxystyrene, 3-propyl-4-hydroxystyrene, 3-propyl-4-hydroxystyrene, 3-t-butyl-4. −
Hydroxystyrene, 3-phenyl-4-hydroxystyrene, 3-naphthyl-4-hydroxystyrene, 3-
Benzyl-4-hydroxystyrene, styryl-4-hydroxystyrene, 3-vinyl-4-hydroxystyrene, 3-propenyl-4-hydroxystyrene, 4-vinyl-3-hydroxystyrene, 4-propenyl-3-
Examples thereof include hydroxystyrene and 3-cumyl-4-hydroxystyrene. Among these, p-hydroxystyrene, 3-ethyl-4-hydroxystyrene, 3-styryl-4-hydroxystyrene, and 3-cumyl-4-hydroxystyrene are preferable.

Specific examples of the compound (a) include, for example, salicyl alcohol, 2-hydroxymethylparacresol, 2-hydroxymethylphenol derivatives such as 4,6-dimethyl-2-hydroxymethylphenol; 2-hydroxy. 2-Hydroxybenzyl chloride derivatives such as benzyl chloride, 2-hydroxy-5-methylbenzyl chloride, 3,5-dimethyl-2-hydroxybenzyl chloride; or 2-dimethylaminomethylphenol, 2-dimethylaminomethylparacresol, 4 There may be mentioned 2-dimethylaminomethylphenol derivatives such as 6,6-dimethyl-2-dimethylaminomethylphenol.

Polymers of hydroxystyrenes, that is, polyhydroxystyrenes, can be obtained by polymerizing hydroxystyrenes by radical polymerization, cationic polymerization, anionic polymerization, thermal polymerization, or Ma.
cromolecules, 1989, 22, 509-
516 and the like, the phenolic hydroxyl group of the corresponding monomer is converted to t-butyl group, acetyl group, t
-A method in which a polymer is obtained by polymerizing while protecting it with a butoxycarbonyl group, a trialkylsilyl group or the like, and then hydrolyzing those protecting groups can be mentioned.

A catalyst is advantageously used in the reaction of the hydroxystyrenes with the compound (a) or the reaction of the polymer of the hydroxystyrenes with the compound (a). Examples of commonly used acid catalysts include inorganic Bronsted acids such as hydrochloric acid, nitric acid and sulfuric acid, organic Bronsted acids such as formic acid, oxalic acid and acetic acid and AlCl ₃ , FeBr ₃ and BB.
Mention may be made of acidic catalysts such as Lewis acids such as r ₃ .

The reaction medium in the above reaction may be one that does not deactivate the catalyst or inhibit the reaction, and examples thereof include dioxane and tetrahydrofuran. The amount of these reaction media used is usually 20 to 1,000 parts by weight per 100 parts by weight of the reaction raw material.

The amount of the compound (a) used is preferably 0.05 to 2 mol, more preferably 0.1 to 2 mol, per 1 mol of the hydroxystyrene (in the case of the polymer, the repeating unit of hydroxystyrene). It is 1.0 mol.

The reaction temperature can be appropriately adjusted depending on the reactivity of the reaction raw materials, but is usually 10 to 200.
C., preferably 70 to 150.degree.

The radiation-sensitive agent used in the present invention is a compound which generates an acid upon irradiation with radiation (hereinafter, referred to as
"Photoacid generator") or a compound that decomposes by irradiation to crosslink the polymer (hereinafter referred to as "photocrosslinker")
Is preferably used. Examples of the photoacid generator include onium salts, halogen-containing compounds, diazoketone compounds, sulfone compounds, sulfonic acid compounds, and nitrobenzyl compounds. Specifically, the compounds shown below can be exemplified.

Onium salt: Iodonium salt, sulfonium salt, phosphonium salt, diazonium salt, ammonium salt and the like can be mentioned. Preferably, the following formula (5)

[0034]

[Chemical 6]

A compound represented by the following formula (6)

[0036]

[Chemical 7]

A compound represented by the following formula (7)

[0038]

[Chemical 8]

Examples thereof include compounds represented by:

Halogen-containing compounds: haloalkyl group-containing hydrocarbon compounds, haloalkyl group-containing heterocyclic compounds and the like can be mentioned, preferably the following formula (8):

[0041]

[Chemical 9]

A compound represented by the following formula (9)

[0043]

[Chemical 10]

Examples thereof include compounds represented by:

Diazoketone compound: 1,3-diketo-2
-A diazo compound, a diazobenzoquinone compound, a diazonaphthoquinone compound and the like can be mentioned, and preferably the following formula (10)

[0046]

[Chemical 11]

A compound represented by the following formula (11)

[0048]

[Chemical 12]

A compound represented by the following formula (12)

[0050]

[Chemical 13]

A compound represented by the following formula (13)

[0052]

[Chemical 14]

A compound represented by the following formula (14)

[0054]

[Chemical 15]

A compound represented by the following formula (15)

[0056]

[Chemical 16]

Examples thereof include compounds represented by:

Sulfone compound: β-ketone sulfone, β
-Sulfonyl sulfone and the like can be mentioned. Preferably, the following formula (16)

[0059]

[Chemical 17]

Examples thereof include compounds represented by:

Nitrobenzyl compounds: Nitrobenzyl sulfonate compounds, dinitrobenzyl sulfonate compounds and the like can be mentioned. Preferably, the following formula (1
7)

[0062]

[Chemical 18]

Examples thereof include compounds represented by:

Sulfonic acid compounds: alkyl sulfonic acid ester, haloalkyl sulfonic acid ester, aryl sulfonic acid ester, imino sulfonate and the like can be mentioned, preferably the following formula (18)

[0065]

[Chemical 19]

A compound represented by the following formula (19)

[0067]

[Chemical 20]

A compound represented by the following formula (20)

[0069]

[Chemical 21]

Examples thereof include compounds represented by: Examples of the photocrosslinking agent include azide compounds. Specifically, the compounds shown below can be exemplified.

Azide compounds: monoazide compounds, bisazide compounds, monosulfonyl azide compounds, bissulfonyl azide compounds and the like can be mentioned. Preferably 1-azidopyrene, p-azidobenzophenone, 4 '
-Methoxy-4-azidodiphenylamine, 4-azidobenzal-2'-methoxyacetophenone, 4-azido-4'-nitrophenylazobenzene, 4,4'-diazidobenzophenone, 4,4'-diazidobenzomethane, 4, 4'-diazidostilbene, 4,4'-diazidochalcone, 4,4'-diazidodiphenyl sulfone, 3,
4'-diazidodiphenyl sulfone, 3,3'-diazidodiphenyl sulfone, 2,6-di (4'-azidobenzal) cyclohexane, 2,6-di (4'-azidobenzal) 4-methylcyclohexane, sulfonylazidobenzene , P-sulfonyl azidotoluene, p-bis (sulfonyl azido) benzene, 4,4′-bis (sulfonyl azido) benzophenone and the like.

Of these radiation-sensitive agents, photoacid generators are preferable, and onium salts and diazoketone compounds are particularly preferable. The content of these radiation-sensitive agents is preferably 1 to 100 parts by weight, and more preferably 3 to 50 parts by weight, based on 100 parts by weight of the polymer (A). If it is less than 1 part by weight, it is difficult to obtain sufficient pattern forming ability,
If it exceeds 100 parts by weight, scum tends to occur when a pattern is formed as a resist.

The composition of the present invention further comprises, if necessary,
Various compounding agents such as a dissolution inhibitor, a dissolution accelerator, an acid crosslinking agent and a surfactant can be added.

The dissolution inhibitor reduces the solubility of the polymer (A) in a developing solution consisting of an alkaline aqueous solution before irradiation with radiation, and after irradiation with radiation, it is cleaved by the acid generated by the photoacid generator to give a resist. It is a compound that improves the solubility in a developing solution consisting of an alkaline aqueous solution used at the time of pattern formation. The dissolution inhibitor can therefore be used without particular limitation as long as it is a compound having such properties.

[0075]

[Chemical formula 22]

[0076]

[Chemical formula 23]

Examples thereof include compounds represented by: In the above formula, R ⁴³ is a substituted methyl group, a 1-substituted ethyl group, a silyl group, a germyl group or an alkoxycarbonyl group. Here, examples of the substituted methyl group include a methoxymethyl group, a methylthiomethyl group, a methoxyethoxymethyl group, a tetrahydropyranyl group, a tetrahydrothiopyranyl group, a tetrahydrofuranyl group, a tetrahydrothiofuranyl group, a benzyloxymethyl group, and phenacyl. Group, bromophenacyl group, methoxyphenacyl group, α
1-substituted ethyl such as methylphenacyl group, cyclopropylmethyl group, cyclopentyl group, cyclohexyl group, benzyl group, triphenylmethyl group, diphenylmethyl group, bromobenzyl group, nitrobenzyl group, methoxybenzyl group, piperonyl group As the group, 1-methoxyethyl group, 1-ethoxyethyl group, isopropyl group, t-
A butyl group, a 1,1-dimethylpropyl group, etc., a silyl group such as a trimethylsilyl group, a triethylsilyl group,
A t-butyldimethylsilyl group, an isopropyldimethylsilyl group, a phenyldimethylsilyl group, and the like, and a germyl group as a trimethylgermyl group, a triethylgermyl group, a t-butyldimethylgermyl group, an isopropyldimethylgermyl group, a phenyldimethylgel. Such as a mill base,
Examples of the alkoxycarbonyl group include methoxycarbonyl group, ethoxycarbonyl group, t-butoxycarbonyl group and the like.

Especially when a photoacid generator is used, it is preferable to add a dissolution inhibitor. The above dissolution inhibitor is used in an amount of preferably 100 parts by weight or less, more preferably 10 to 50 parts by weight, based on 100 parts by weight of the polymer (A). The above dissolution inhibitors are preferably used to obtain a positive resist composition.

The dissolution accelerator is added to accelerate the alkali solubility of the polymer (A). As such a dissolution accelerator, a phenol compound having about 2 to 6 benzene rings is used. Is mentioned. The content of the dissolution accelerator is usually 50 per 100 parts by weight of the polymer (A).
It is less than or equal to parts by weight.

The acid cross-linking agent is a compound that cross-links the polymer (A) with the acid generated by the photo-acid generator and reduces the solubility in the alkaline aqueous solution used when forming the resist pattern. Examples of such an acid crosslinking agent include an epoxy group,

[0081]

[Chemical formula 24]

[0082]

[Chemical 25]

Or

[0084]

[Chemical formula 26]

Aromatic compounds having groups selected from are preferred. The amount of the acid crosslinking agent is usually 10
It is usually 100 parts by weight or less per 0 parts by weight. In order to obtain a negative resist composition, the above acid crosslinking agent is preferably used.

The surface active agent is added to improve the coatability and developability of the composition. Examples of such surface active agent include polyoxyethylene lauryl ether and polyoxyethylene stearyl ether. ,
Polyoxyethylene oleyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene nonyl phenyl ether, polyethylene glycol dilaurate, polyethylene glycol distearate, Ftop EF301, EF303, EF352 (trade name,
(Made by Shin-Akita Kasei Co., Ltd.), Megafax F171, F17
2, F173 (trade name, manufactured by Dainippon Ink and Chemicals), Florard FC430, FC431 (trade name, manufactured by Sumitomo 3M Limited), Asahi Guard AG710, Surflon S-38.
2, SC-101, SC-102, SC-103, SC
-104, SC-105, SC-106 (trade name, manufactured by Asahi Glass Co., Ltd.), organosiloxane polymer KP341 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), acrylic acid-based or methacrylic acid-based (co) weight polyflow No. 75. , No.95
(Trade name, manufactured by Kyoeisha Yushi Kagaku Kogyo Co., Ltd.) and the like.

The content of these surfactants is usually 2 parts by weight or less per 100 parts by weight of the solid content of the composition. Examples of other additives include antihalation agents composed of azo compounds and amine compounds, sensitizers, adhesion promoters, storage stabilizers, defoamers and the like.

In the composition of the present invention, the above-mentioned polymer (A), radiation sensitive agent and various compounding agents optionally mixed are dissolved in a solvent so that the solid content concentration is 20 to 40% by weight. Monkey

Examples of the solvent used at this time include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol methyl ether acetate, propylene glycol propyl. Ether acetate, toluene, xylene, methyl ethyl ketone, cyclohexanone, ethyl 2-hydroxypropionate, 2
-Ethyl hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutanoate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, 3 -Methyl ethoxypropionate, ethyl acetate, butyl acetate and the like can be used. Furthermore, N-methylformamide, N, N-dimethylformamide, N-methylformanilide, N-methylacetamide, N, N-dimethylacetamide, N-
Methylpyrrolidone, dimethyl sulfoxide, benzyl ethyl ether, dihexyl ether, acetonyl acetone, isophorone, caproic acid, caprylic acid, 1-octanol, 1-nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate. It is also possible to add a high boiling solvent such as γ-butyrolactone, ethylene carbonate, propylene carbonate or phenyl cellosolve acetate.

The composition of the present invention is applied to a silicon wafer or a wafer coated with aluminum, for example, by spin coating, flow coating, roll coating or the like to form a radiation-sensitive layer, and a predetermined mask. The pattern is formed by irradiating the radiation-sensitive layer with radiation through the pattern and developing with a developing solution.

When the composition of the present invention is used as a resist, the composition is coated on a wafer,
70-140 after pre-baking and irradiation
The effect of the present invention can be further improved by carrying out an operation of heating at ° C and then developing.

The developer of the composition of the present invention includes, for example, 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, 1,5-diazabicyclo- (4.
An alkaline aqueous solution prepared by dissolving an alkaline compound such as 3.0) -5-nonane to a concentration of, for example, 1 to 10% by weight is used.

A water-soluble organic solvent, for example, alcohols such as methanol and ethanol, and a surfactant may be added to the developing solution in an appropriate amount. When developing is performed using a developing solution composed of such an alkaline aqueous solution, generally, rinsing with water is subsequently performed.

[0094]

The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. The measurement of Mw and the evaluation of the resist in the examples are carried out by the following methods.

Mw: Toyo Soda GPC column (G2
000H _XL 2 Pieces, G3000H _XL 1 Piece, G4000H _XL
1 column), the flow rate was 1.5 ml / min, the elution solvent was tetrahydrofuran, and the column temperature was 40 ° C., and the gel permeation chromatography method using monodisperse polystyrene as a standard was used for measurement.

Synthesis Example 1 A flask equipped with a reflux tube and a dropping funnel was charged with poly (4-hydroxystyrene) (Mw = 22,000) 2.
4 g and p-toluenesulfonic acid monohydrate 1.9 g
(0.01 mol) was charged and dissolved in 100 ml of dioxane. The temperature of the flask was raised and, under reflux, 12.4 g (0.1%) of salicyl alcohol dissolved in 50 ml of dioxane.
1 mol) was added dropwise with a dropping funnel over 2 hours. After continuing the reaction for an additional 1 hour, the reaction solution was poured into water,
A crude polymer was obtained by the reprecipitation method. The polymer was filtered off, washed with water and methanol to remove the acid and low molecular weight components, and dried to obtain a polymer with Mw = 24,000. Let this polymer be a polymer (A1).

Synthesis Example 2 A flask similar to that used in Synthesis Example 1 was charged with 24 g of poly (4-hydroxystyrene) (Mw = 22,000) and 0.95 g of p-toluenesulfonic acid (5 × 10 ⁻³ mol).
It was dissolved in 00 ml of dioxane. Heat up the flask,
It was dissolved in 50 ml of dioxane under reflux. 4,6
-Dimethyl-2-hydroxymethylphenol 12.3
g (0.08 mol) was added dropwise with a dropping funnel over 1 hour. After continuing the reaction for an additional 1 hour, the acid and low-molecular components were removed in the same manner as in Synthesis Example 1, dried, and Mw =
26,000 polymers were obtained. This polymer is referred to as polymer (A
2).

Synthesis Example 3 A flask similar to that used in Synthesis Example 1 was charged with 24 g of poly (4-hydroxystyrene) (Mw = 22,000) and 1.9 g (0.01 mol) of p-toluenesulfonic acid (100 m).
It was dissolved in 1 of dioxane. The flask was heated and dissolved in 50 ml of dioxane under reflux. 2-Hydroxymethylparacresol 12.5 g (0.09 mol) was added dropwise with a dropping funnel over 2 hours. After continuing the reaction for further 2 hours, the acid and low molecular components were removed in the same manner as in Synthesis Example 1 and dried to obtain a polymer having Mw = 25,000. Let this polymer be a polymer (A3).

Synthesis Example 4 A flask similar to that of Synthesis Example 1 was charged with 24 g of poly (4-hydroxystyrene) (Mw = 22,000) and 20 ml of 36% hydrochloric acid aqueous solution, and dissolved in 100 ml of dioxane. The flask was heated and dissolved in 50 ml of dioxane under reflux. 18.6-g (0.1 mol) of 4,6-dimethyl-2-dimethylaminomethylphenol was added dropwise with a dropping funnel over 1 hour. After continuing the reaction for an additional 1 hour, the acid and low molecular components were removed in the same manner as in Synthesis Example 1 and dried to obtain a polymer having Mw = 26,500. Let this polymer be a polymer (A4).

Synthesis Example 5 A flask similar to that used in Synthesis Example 1 was charged with 24 g of poly (4-hydroxystyrene) (Mw = 32,000) and 1.0 g of p-toluenesulfonic acid and dissolved in 100 ml of dioxane. The flask is heated to 100 at reflux.
2-hydroxymethyl-4 dissolved in ml dioxane
-Methylphenol 20.7 g (0.15 mol) was added dropwise with a dropping funnel over 1.5 hours. After continuing the reaction for an additional 1 hour, the acid and low molecular components were removed in the same manner as in Synthesis Example 1 and dried to obtain a polymer having Mw = 38,000. Let this polymer be a polymer (A5).

Example 1 100 parts by weight of the polymer (A1) obtained in Synthesis Example 1, 3.5 parts by weight of triphenylsulfonium trifluoromethasulfonate as a photoacid generator, and 1 as a dissolution inhibitor were used.
T of 1,1-tris (4-hydroxyphenyl) ethane
ert-butoxy carbonate (esterification rate 100
%) 30 parts by weight was dissolved in 470 parts by weight of ethyl 2-hydroxypropionate and filtered through a 0.2 μm membrane filter to obtain a resist solution.

The above resist solution was applied onto a silicon wafer by a spinner and then prebaked at 100 ° C. for 100 seconds to form a resist film having a thickness of 1.0 μm. A mask having a pattern is brought into close contact with the resist film, and the wavelength of 2
After irradiating with a 48 nm KrF excimer laser generator (“MBK-400TL-N” manufactured by Admon Science Co., Ltd.), it was baked at 110 ° C. for 60 seconds and then baked. Next, it was developed by an immersion method in a tetramethylammonium hydroxide aqueous solution at 23 ° C. for 1 minute, and rinsed with ultrapure water for 30 seconds.

As a result, a positive pattern with a line and space of 0.30 μm could be resolved with a good rectangular shape. There was no development residue in the radiation-irradiated portion, and there was no film loss in the radiation-irradiated portion. Moreover, heat resistance and the like were also good.

Example 2 100 parts by weight of the polymer (A2) obtained in Synthesis Example 2 and 1,2-naphthoquinonediazide-4- of 2,3,4,4'-tetrahydroxybenzophenone as a photoacid generator. 15 parts by weight of sulfonic acid ester (average esterification rate 80%), tetrahydropyranyl ether of polyhydroxystyrene as a dissolution inhibitor (average etherification rate 50%, M
10 parts by weight (w = 26,000) were dissolved in 390 parts by weight of methyl 3-methoxypropionate. After applying the above resist solution on a silicon wafer with a spinner, 90 ° C
And prebaked for 90 seconds to form a resist film having a thickness of 1.0 μm. Then, in the same manner as in Example 1, irradiation with radiation, baking after irradiation with radiation, development, and rinsing were performed.

As a result, a positive pattern having a line and space of 0.30 μm could be resolved with a good rectangular shape. There was no development residue in the radiation-irradiated portion, and there was no film loss in the radiation-irradiated portion. Moreover, heat resistance and the like were also good.

Example 3 90 parts by weight of the polymer (A3) obtained in Synthesis Example 3 and 1,1,3-tris (2,5-dimethyl-4) as a photoacid generator.
-Hydroxyphenyl) -3-phenylpropane,
25 parts by weight of 1,2-naphthoquinonediazide-5-sulfonate (average esterification rate 80%) 1,1-
10 parts by weight of bis (4-hydroxyphenyl) -1-phenylethane was added to methyl 3-methoxypropionate 3
It was dissolved in 90 parts by weight. 90 ° C. as in Example 2
And prebaked for 90 seconds to form a resist film.

The resist film was exposed by using a reduction projection exposure machine (NSR-1505i6A manufactured by Nikon Co .; the numerical aperture of the lens was 0.45) having a wavelength of 365 nm.
After exposure at 60 ° C. for 60 seconds, baking was performed. Next, it was developed by an immersion method in a tetramethylammonium hydroxide aqueous solution at 23 ° C. for 1 minute, and rinsed with ultrapure water for 30 seconds.

As a result, a positive pattern of 0.38 μm line and space could be resolved with a good rectangular shape. There was no development residue in the radiation-irradiated portion, and there was no film loss in the radiation-irradiated portion. Moreover, heat resistance and the like were also good.

Example 4 100 parts by weight of the polymer (A4) obtained in Synthesis Example 4, 5 parts by weight of 2,6-dinitrobenzyl-4-nitrobenzenesulfonate as a photoacid generator and 1,2 as a dissolution inhibitor.
T of 1,1-tris (4-hydroxyphenyl) ethane
20 parts by weight of ert-butyl ether (ester ratio 100%) was dissolved in methyl 3-methoxypropionate. The resist solution was applied onto a silicon wafer with a spinner and prebaked at 100 ° C. for 90 seconds to form a resist film having a thickness of 1.0 μm.

A mask having a pattern was brought into close contact with the resist film, irradiated with radiation in the same laser generator as in Example 1, and then exposed at 90 ° C. for 100 seconds and baked. Next, it was developed by an immersion method in a tetramethylammonium hydroxide aqueous solution at 23 ° C. for 1 minute, and rinsed with ultrapure water for 30 seconds.

As a result, a positive pattern with a line and space of 0.30 μm could be resolved with a good rectangular shape. There was no development residue in the radiation-irradiated portion, and there was no film loss in the radiation-irradiated portion. Moreover, heat resistance and the like were also good.

Example 5 100 parts by weight of the polymer (A5) obtained in Synthesis Example 5, 5 parts by weight of triphenylsulfonium hexafluoroantimonate as a photoacid generator, and 45 parts by weight of hexamethylmethoxymelamine as a cross-linking agent were added. , Methyl 3-methoxypropionate. The resist solution was applied onto a silicon wafer with a spinner and prebaked at 90 ° C. for 120 seconds to form a resist film.

A mask having a pattern was brought into close contact with the resist film, irradiated with radiation in the same laser generator as in Example 1, and then exposed at 90 ° C. for 120 seconds and baked. Next, it was developed by an immersion method in a tetramethylammonium hydroxide aqueous solution at 23 ° C. for 1 minute, and rinsed with ultrapure water for 30 seconds.

As a result, a negative line-and-space pattern of 0.30 μm could be resolved. There was no development residue in the radiation-irradiated portion, and there was no film loss in the radiation-irradiated portion. Moreover, heat resistance and the like were also good.

[0115]

The radiation-sensitive resin composition of the present invention is suitable as a photoresist composition excellent in performance such as developability, pattern shape, resolution, heat resistance and residual film property. Further, the radiation-sensitive resin composition of the present invention is particularly suitable for deep ultraviolet rays such as excimer laser and X-ray such as synchrotron radiation.
Since it can be applied to any radiation such as a charged particle beam such as a beam and an electron beam, it can be advantageously used as a resist for manufacturing an integrated circuit, which is expected to be further miniaturized in the future.

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

Claims (1)

[Claims] 1. The following formula (1): A radiation-sensitive resin composition comprising a polymer having a repeating unit represented by and a radiation-sensitive agent.