JPH0694453B2 - Method for producing radiation-sensitive agent for positive resist - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a radiation sensitive agent for positive resist. Specifically, the present invention is sensitive to radiation such as ultraviolet rays, deep ultraviolet rays, X-rays, electron beams, molecular beams, γ rays, synchrotron radiation, and proton beams by mixing with an alkali-soluble resin. The present invention relates to a method for producing a radiation-sensitive agent for a positive resist, which provides a positive resist suitable as a resist for a positive resist.

[0002]

2. Description of the Related Art Conventionally, as a resist for producing an integrated circuit, a negative resist in which a bisazide compound is mixed with a cyclized rubber and a positive resist in which a 1,2-quinonediazide compound is mixed with an alkali-soluble resin are known. . In the negative resist, the bisazide compound desorbs nitrogen to become nitrene by UV irradiation, and three-dimensionally crosslinks the cyclized rubber, so that the solubility of the UV-irradiated part and the non-irradiated part in the developing solution composed of the solvent of the cyclized rubber is improved. There is a difference, and patterning is caused by this, but even if it is said that crosslinking does not completely cure the ultraviolet irradiation portion, there is a drawback that the resist pattern swells greatly in the developer and the resolution of the resist pattern is poor. .

On the other hand, the positive resist contains an alkali-soluble resin and an alkali-insoluble 1,2-quinonediazide compound, so that it hardly dissolves in a developer composed of an alkaline aqueous solution and hardly swells. Even if the 1,2-quinonediazide compound is changed to indenecarboxylic acid and developed with a developing solution consisting of an alkaline aqueous solution, the change of the unirradiated portion to be the resist pattern is extremely small.
In addition, a high resolution resist pattern can be obtained. As a result, in recent years, where high integration of integrated circuits is required, positive resists having excellent resolution are often used. However, even in the case of this positive type resist, it is difficult to obtain a resist pattern faithful to the mask unless the exposed portion is rapidly developed to the portion in contact with the wafer. When the width is as narrow as 1 μm or less, the developability of the hem portion of the resist pattern is large and the resolution is affected. Therefore, as the degree of integration increases year by year, there is a strong demand for development of a positive resist which has good developability and can resolve a resist pattern of 1 μm or less.

[0004]

The object of the present invention is to solve the above-mentioned problems of the prior art and to use a positive resist suitable as a resist for producing an integrated circuit having good developability and high resolution. Another object of the present invention is to provide a method for producing a radiation sensitive agent for positive resist.

[0005]

DISCLOSURE OF THE INVENTION The present invention relates to a radiation-sensitive agent for positive resist which is mixed with an alkali-soluble resin to give a positive resist, and comprises tetrahydroxybenzophenone and 1,2-quinonediazide sulfonic acid halide as amines. The present invention provides a production method characterized by carrying out a condensation reaction in the presence of. The radiation sensitive agent for positive resist of the object of the present invention is a 1,2-quinonediazidesulfonic acid ester of tetrahydroxybenzophenone which is a condensation reaction product of tetrahydroxybenzophenone and 1,2-quinonediazidesulfonic acid halide. , Characterized by using amines as a basic catalyst in the condensation reaction, based on the characteristics, the present invention, the proportion of the tetraester in the condensation reaction product is high, excellent developability, high resolution. It is possible to obtain a positive resist having the above, and it is possible to produce a radiation sensitive agent for a positive resist which does not have a trace amount of metal residue derived from a basic catalyst using a metal.

The radiation sensitive agent for positive resist of the present invention is
2,3,4,4'-tetrahydroxybenzophenone,
One or several tetrahydroxybenzophenones such as 2,2 ′, 4,4′-tetrahydroxybenzophenone and 2,2 ′, 4,6-tetrahydroxybenzophenone, and 1,2-naphthoquinonediazide-5-sulfone Acid chloride, 1,2-naphthoquinonediazide-4-sulfonic acid chloride, 1,2-benzoquinonediazide-4-
It can be obtained by subjecting 1,2-quinonediazide sulfonic acid halide such as sulfonic acid chloride to one or several kinds of condensation reaction in the presence of amines.

As the amines, for example, trimethylamine, triethylamine, tripropylamine, pyridine, tetramethylammonium hydroxide and the like are used. The amount of these amines used is 1, 2,
The amount is usually 0.8 to 2 mol, preferably 1 to 1.5 mol, per 1 mol of quinonediazide sulfonic acid halide.

The condensation reaction is usually carried out in the presence of a solvent. Examples of the solvent used at this time include dioxane, tetrahydrofuran, acetone, methyl ethyl ketone, γ-butyrolactone, N-methylpyrrolidone,
Examples include N, N-dimethylacetamide, N, N-dimethylformamide, ethylene carbonate, propylene carbonate and the like. The amount of these solvents used is usually 100 to 1000 parts by weight with respect to 100 parts by weight of the reaction raw material. Although the temperature of the condensation reaction varies depending on the solvent used, it is usually -20.
-60 ° C, preferably 0-40 ° C. As a purification method after the condensation reaction, the by-produced hydrochloride is filtered, or water is added to dissolve the hydrochloride, followed by reprecipitation purification with a large amount of acidic water such as dilute hydrochloric acid aqueous solution, followed by drying. The method of doing can be illustrated. By using amines as the basic catalyst for the condensation reaction, the trace amount of metal based on the trace amount of the residue of the catalyst is not mixed in the condensation reaction product.

The radiation sensitive agent for positive resist of the present invention is
Specifically, for example, 2,3,4,4′-tetrahydroxybenzophenone-1,2-naphthoquinonediazide-5
-Sulfonic acid ester, 2,3,4,4'-tetrahydroxybenzophenone-1,2-naphthoquinonediazide-4-sulfonic acid ester, 2,3,4,4'-tetrahydroxybenzophenone-1,2-benzoquinonediazide -4-sulfonic acid ester etc. are mentioned. These radiation-sensitive agents for positive resists are condensation reaction products of tetrahydroxybenzophenone and 1,2-quinonediazidesulfonic acid halide, and in the condensation reaction of tetrahydroxybenzophenone and 1,2-quinonediazidesulfonic acid halide, A monosulfonic acid ester, a disulfonic acid ester, a trisulfonic acid ester of tetrahydroxybenzophenone, and a tetrasulfonic acid ester in which all the hydroxyl groups contained in tetrahydroxybenzophenone have reacted are formed.

In the case of mixing the radiation-sensitive agent for positive resist produced by the present invention with an alkali-soluble resin to obtain a positive resist which is sensitive to radiation, and particularly suitable as a resist for producing an integrated circuit, tetrahydroxy is used. The 1,2-quinonediazide sulfonic acid ester of benzophenone has a tetraester ratio of 10 to 80% by weight, preferably 20 to 70% by weight. When the proportion of the tetraester is less than 10% by weight, it is easy to dissolve in a developer composed of an alkaline aqueous solution even when it is not exposed to radiation when used as a positive resist, and it becomes difficult to perform high resolution patterning. When it exceeds 80% by weight, residual development is observed and it becomes difficult to obtain high resolution. Thus, in a positive resist, the radiation sensitive agent for a positive resist, that is, the proportion of the tetraester in the 1,2-quinonediazide sulfonic acid ester of tetrahydroxybenzophenone plays an important role in obtaining a resist pattern with high resolution. I carry it. The present invention is based on the feature that amines are used as a basic catalyst in the condensation reaction, and the condensation reaction product is different from the case where other basic catalysts, for example, inorganic alkalis such as sodium carbonate and sodium hydrogen carbonate are used. A radiation sensitive agent for positive resist having a high proportion of tetraester can be produced. The increase in the proportion of the tetraester is significant for the preparation of a positive resist for obtaining a resist pattern having excellent developability and high resolution. Further, there is an advantage that it is possible to produce a radiation sensitive agent for positive resist which is free of metal residue based on a trace amount of an inorganic alkali catalyst which is very difficult to purify which affects the performance of integrated circuits. As the ratio of triester, diester and monoester other than tetraester, the ratio of the total amount of diester and triester is usually 20 to 60% by weight, preferably 30 to 60% by weight, and the ratio of monoester is usually 30% by weight. % Or less, preferably 20% by weight or less.

The radiation-sensitive agent for positive resist manufactured by the present invention is based on 100 parts by weight of the alkali-soluble resin.
Usually, it is used in an amount of 5 to 100 parts by weight, preferably 10 to 50 parts by weight. If this blending amount is less than 5 parts by weight, the amount of carboxylic acid produced by the 1,2-quinonediazidesulfonic acid ester of tetrahydroxybenzophenone that absorbs radiation is small, and thus patterning is difficult. If the amount exceeds the range, all of the added 1,2-quinonediazide sulfonic acid ester of tetrahydroxybenzophenone cannot be decomposed by irradiation for a short time, and development with a developing solution composed of an alkaline aqueous solution becomes difficult.

When the radiation sensitive agent for positive resist prepared in the present invention is mixed with an alkali-soluble resin to form a positive resist sensitive to radiation, the 1,2-quinonediazide sulfonic acid ester of tetrahydroxybenzophenone is used. 100 parts by weight or less, preferably 40 parts by weight or less, of another 1,2-quinonediazide compound may be added to 100 parts by weight.

Other 1,2-quinonediazide compounds used in this case include, for example, p-cresol-1,2-
1,2- (poly) hydroxybenzene such as benzoquinone diazide-4-sulfonic acid ester, resorcinol-1,2-naphthoquinone diazide-4-sulfonic acid ester, pyrogallol-1,2-naphthoquinone diazide-5-sulfonic acid ester Quinone diazide sulfonic acid esters; 2,4-dihydroxyphenyl-propyl ketone-1,2-benzoquinone diazide-4-sulfonic acid ester, 2,4-dihydroxyphenyl-n-hexyl ketone-1,2-naphthoquinone diazide-4- Sulfonic acid ester, 2,4-dihydroxybenzophenone-
1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4-trihydroxyphenyl-n-hexylketone-1,2-naphthoquinonediazide-4-sulfonic acid ester, 2,3,4-trihydroxybenzophenone -1,2-naphthoquinonediazide-4-sulfonic acid ester, 2,3,4-trihydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,4,6-trihydroxybenzophenone-
1,2-naphthoquinonediazide-4-sulfonic acid ester, 2,4,6-trihydroxybenzophenone-1,
2,2-naphthoquinonediazide-5-sulfonic acid ester or other (poly) hydroxyphenylalkylketone or (poly) hydroxyphenylarylketone 1,2-
Quinonediazide sulfonates; bis (p-hydroxyphenyl) methane-1,2-naphthoquinonediazide-4-sulfonate, bis (2,4-dihydroxyphenyl) methane-1,2-naphthoquinonediazide-5-sulfonate Ester, bis (2,3,4-trihydroxyphenyl) methane-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,2-bis (p-hydroxyphenyl) propane-1,2-naphthoquinonediazide-4 -Sulfonic acid ester, 2,2-bis (2,2
4-dihydroxyphenyl) propane-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,2-bis (2,3,4-trihydroxyphenyl) propane-
1,2-naphthonequinonediazide-5-sulfonic acid ester and other bis [(poly) hydroxyphenyl] alkane 1,2-quinonediazidesulfonic acid esters; 3,5
-Dihydroxybenzoic acid lauryl-1,2-naphthoquinonediazide-4-sulfonic acid ester, 2,3,4-trihydroxybenzoic acid phenyl-1,2-naphthoquinonediazide-5-sulfonic acid ester, 3,4,5- (Poly) hydroxybenzoic acid such as propyl-1,2-naphthoquinonediazide-5-sulfonic acid ester of trihydroxybenzoic acid, phenyl-1,2-naphthoquinonediazide-5-sulfonic acid ester of 3,4,5-trihydroxybenzoic acid 1,2-quinonediazide sulfonic acid esters of acid alkyl esters or (poly) hydroxybenzoic acid aryl esters; bis (2,5-dihydroxybenzoyl) methane-1,2-naphthoquinonediazide-4-sulfonic acid ester, bis (2 , 3,4-trihydroxybenzoyl) meta 1,2-naphthoquinonediazide -
5-sulfonic acid ester, bis (2,4,6-trihydroxybenzoyl) methane-1,2-naphthoquinonediazide-5-sulfonic acid ester, p-bis (2,5-dihydroxybenzoyl) benzene-1,2- Naphthoquinonediazide-4-sulfonic acid ester, p-bis (2,2
3,4-trihydroxybenzoyl) benzene-1,2
-Naphthoquinonediazide-5-sulfonic acid ester, p
1-bis [(poly) hydroxybenzoyl] alkane such as bis (2,4,6-trihydroxybenzoyl) benzene-1,2-naphthoquinonediazide-5-sulfonic acid ester or bis [(poly) hydroxybenzoyl] benzene , 2-quinonediazide sulfonates; and ethylene glycol di (3,5-dihydroxybenzoate) -1,2-naphthoquinonediazide-
5-sulfonic acid ester, polyethylene glycol di (3,4,5-trihydroxybenzoate) -1,2
Examples include 1,2-quinonediazidesulfonic acid esters of (poly) ethylene glycol di [(poly) hydroxybenzoate] such as naphthoquinonediazide-5-sulfonic acid ester.

Typical examples of the alkali-soluble resin to which the radiation sensitive agent for positive resist produced in the present invention can be added include alkali-soluble novolak resins (hereinafter simply referred to as "novolak resins"). The novolak resin is obtained by polycondensing phenols and aldehydes in the presence of an acid catalyst. Examples of phenols include phenol, o-cresol, m-cresol, p-cresol, o-ethylphenol, and m.
-Ethylphenol, p-ethylphenol, o-butylphenol, m-butylphenol, p-butylphenol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 3,4-xylenol,
3,5-xylenol, 2,3,5-trimethylphenol, p-phenylphenol, hydroquinone, catechol, resorcinol, 2-methylresorcinol, pyrogallol, α-naphthol, bisphenol A, dihydroxybenzoic acid ester, gallic acid ester, etc. Of these phenols, phenol, o-cresol, m-cresol, p-cresol, 2,5-
Xylenol, 3,5-xylenol, 2,3,5-trimethylphenol, resorcinol, 2-methylresorcinol and bisphenol A are preferred. These phenols may be used alone or in admixture of two or more.

Examples of the aldehydes include formaldehyde, paraformaldehyde, acetaldehyde, propylaldehyde, benzaldehyde, phenylacetaldehyde, α-phenylpropylaldehyde, β-phenylpropylaldehyde, o-hydroxybenzaldehyde, m-hydroxybenzaldehyde, p-hydroxybenzaldehyde. , O-chlorobenzaldehyde,
m-chlorobenzaldehyde, p-chlorobenzaldehyde, o-nitrobenzaldehyde, m-nitrobenzaldehyde, p-nitrobenzaldehyde, o-methylbenzaldehyde, m-methylbenzaldehyde, p-
Methylbenzaldehyde, p-ethylbenzaldehyde, pn-butylbenzaldehyde and the like are used, and formaldehyde, acetaldehyde and benzaldehyde are preferable among these compounds. These aldehydes may be used alone or in admixture of two or more.
Aldehydes are used in a ratio of preferably 0.7 to 3 mol, particularly preferably 0.7 to 2 mol, per mol of phenols.

As the acid catalyst, for example, inorganic acids such as hydrochloric acid, nitric acid and sulfuric acid, or organic acids such as formic acid, oxalic acid and acetic acid are used. The amount of these acid catalysts used is preferably 1 × 10 ^{−4 to} 5 × 10 ⁻¹ mol per mol of phenols. In the condensation reaction, water is usually used as the reaction medium, but when the phenols used in the condensation reaction do not dissolve in the aqueous solution of aldehydes and become a heterogeneous system from the initial stage of the reaction, hydrophilicity is used as the reaction medium. It is also possible to use a solvent. Examples of these hydrophilic solvents include alcohols such as methanol, ethanol, propanol and butanol, and cyclic ethers such as tetrahydrofuran and dioxane. The amount of these reaction media used is usually 20 to 1 per 100 parts by weight of the reaction raw material.
000 parts by weight. The reaction temperature of the condensation reaction can be appropriately adjusted depending on the reactivity of the reaction raw materials, but usually,
The temperature is 10 to 200 ° C, preferably 70 to 150 ° C. After the condensation reaction is completed, in order to remove the unreacted raw materials, the acid catalyst and the reaction medium existing in the system, the internal temperature is generally set to 130 to
The temperature is raised to 230 ° C., the volatile components are distilled off under reduced pressure, and then the molten novolac resin is drowned on a steel belt or the like and collected.

After the completion of the condensation reaction, the reaction mixture is dissolved in the hydrophilic solvent and added to a precipitating agent such as water, n-hexane or n-heptane to precipitate the novolac resin, and the precipitate is separated. It can also be recovered by heating and drying. Examples of the alkali-soluble resin other than the novolac resin include polyhydroxystyrene or its derivative, styrene-maleic anhydride copolymer, polyvinyl hydroxybenzoate, and carboxyl group-containing methacrylic resin.

These alkali-soluble resins may be used alone or in admixture of two or more. The positive resist comprising the radiation sensitive agent for positive resist and the alkali-soluble resin produced in the present invention may contain a sensitizer in order to improve the sensitivity of the resist. Examples of the sensitizer include 2H-pyrido [3,2-b] -1,4-
Oxazin-3 [4H] ones, 10H-pyrido [3,
2-b] [1,4] -benzothiazines, urazoles, hydantoins, barbituric acids, glycine anhydrides, 1-hydroxybenzotriazoles, alloxanes, maleimides and the like can be mentioned. The compounding amount of the sensitizer is usually 100 parts by weight or less, preferably 60 parts by weight or less with respect to 100 parts by weight of 1,2-quinonediazidesulfonic acid ester.

Further, the positive resist containing the radiation-sensitive agent for positive resist and the alkali-soluble resin produced in the present invention has applicability, for example, striation or development of a radiation-irradiated portion after formation of a dry coating film. Surfactants can be added to improve the properties. Further, a colorant, an adhesion aid, a storage stabilizer, an antifoaming agent and the like can be added to the resist if necessary.

The resist is prepared by dissolving the alkali-soluble resin, the 1,2-quinonediazide sulfonic acid ester, and the above-mentioned various compounding agents in a predetermined amount in a solvent, and filtering the resulting mixture with a filter having a pore size of about 0.2 μm.
Is prepared. Examples of the solvent used at this time include glycol ethers such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether;
Cellosolve esters such as methyl cellosolve acetate and ethyl cellosolve acetate; monooxymonocarboxylic acid esters such as methyl 2-oxypropionate and ethyl 2-oxypropionate; aromatic hydrocarbons such as toluene and xylene; methyl ethyl ketone, cyclohexanone And the like; esters such as ethyl acetate and butyl acetate. These solvents may be used alone or in admixture of two or more.

If necessary, benzyl ethyl ether, dihexyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, acetonylacetone, isophorone, caprons, caprylic acid, 1-octanol, 1-nonanol, benzyl alcohol, benzyl acetate, It is also possible to add a high boiling point solvent such as ethyl benzoate, diethyl oxalate, diethyl maleate, γ-butyrolactone, ethylene carbonate, propylene carbonate, phenyl cellosolve acetate and the like.

As a method of applying the resist to a substrate such as a silicon wafer, the resist is applied at a concentration of 5
Examples include a method in which the solvent is dissolved in the above solvent so as to be 50% by weight and filtered, and then the solution is applied by spin coating, flow coating, roll coating, or the like.

Examples of the developing solution for the resist include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine and diamine. -N-propylamine, triethylamine, methyldiethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, pyrrole, piperidine, 1,8-diazabicyclo (5,4,0) -7-undecene An alkaline aqueous solution prepared by dissolving 1,5-diazahicyclo (4,3,0) -5-nonane and the like is used. An alkaline aqueous solution prepared by adding an appropriate amount of a water-soluble organic solvent, for example, alcohols such as methanol and ethanol or a surfactant to the developer can also be used as the developer.

[0024]

The present invention will be described in more detail with reference to the following examples. Example 1 (1) Production of Radiation Sensitive Agent for Positive Resist 5 Under a light-shielding condition, a stirrer, a dropping funnel and a thermometer were used.
In a 00 ml separable flask, 10.5 g of 2,3,4,4'-tetrahydroxybenzophenone and 1,2
-Naphthoquinonediazide-5-sulfonic acid chloride 3
4.5 g [corresponding to 1,2-naphthoquinonediazide-5-sulfonic acid chloride / 2,3,4,4′-tetrahydroxybenzophenone = 3 (molar ratio)] was further added, and 240 g of dioxane was added and stirred. Dissolved.
Separately, 14.3 g of triethylamine was charged into the dropping funnel, the separable flask was immersed in a water bath kept at 30 ° C., and when the internal temperature became constant at 30 ° C., triethylamine was slowly added dropwise. After adding triethylamine so that the inner temperature does not exceed 35 ° C., the precipitated triethylamine hydrochloride was removed by filtration, and the filtrate was poured into a large amount of dilute hydrochloric acid to precipitate 1,2-quinonediazidesulfonic acid ester. . This was filtered, collected, and dried at 40 ° C. for one day. The yield obtained by measuring the dry weight was 98%. The compositional analysis of the 1,2-quinonediazide sulfonic acid ester thus obtained showed that the proportion of tetraester was 63% by weight, the proportion of the total amount of diester and triester was 32% by weight, and the proportion of monoester was 5% by weight. %
Met. The composition distribution of 1,2-quinonediazide sulfonic acid ester in the present invention was measured by gel permeation chromatography (hereinafter abbreviated as GPC).
The measurement conditions of GPC are as follows. Separation column: Column having an inner diameter of 20 mm and a length of 60 cm filled with polystyrene gel having an average pore diameter of 7 μm Eluent: tetrahydrofuran Flow rate: 2 ml / min Detector: Showa Denko's differential refractometer SHODEX SE3
Type 1 separation column temperature: 25 ° C. Sample injection amount: 100 μl of about 1.0 wt% tetrahydrofuran solution

(2) Production of radiation-sensitive agent compounding resin for positive type resist In a 500 ml flask, 50 g of m-cresol and p were added.
After charging 50 g of cresol, 66 ml of 37% by weight aqueous formaldehyde solution and 0.04 g of oxalic acid were added, the flask was immersed in an oil bath with stirring, the reaction temperature was kept at 100 ° C., and polycondensation was carried out for 6 hours. By doing so, a novolac resin was obtained. After reaction, 30 mm in the system
The pressure was reduced to Hg to remove water, the internal temperature was further raised to 130 ° C., and unreacted substances were distilled off. Then, the molten novolac resin was returned to room temperature and recovered.

(3) Positive resist using radiation sensitive agent for positive resist 20 g of the novolak resin obtained in (2), 2,3,4,4'-tetrahydroxybenzophenone obtained in (1) 5 g of 1,2-naphthoquinonediazide-5-sulfonic acid ester and 60 g of ethyl cellosolve acetate were thoroughly stirred and dissolved at room temperature and then dissolved, and then filtered through a membrane filter having a pore size of 0.2 μm to prepare a positive resist solution. This solution was applied onto a silicon wafer having a silicon oxide film by a spinner and then prebaked at 90 ° C. for 2 minutes to form a resist layer having a thickness of 1.2 μm. Then, using a stepper, through a pattern mask, 0.58
Second, it was irradiated with ultraviolet rays, developed for 60 seconds with a 2.4% by weight aqueous solution of tetramethylammonium hydroxide (hereinafter abbreviated as TMA), rinsed with water, and dried. When the obtained resist pattern was observed with a scanning electron microscope, a portion that could not be completely developed at the joint between the silicon wafer and the resist pattern, that is, no development residue was observed, and a resist pattern with a line width of 0.8 μm was resolved. It was The results are shown in Table 1.

Examples 2 to 4 The amount of triethylamine shown in Table 1 was used in place of 14.3 g of triethylamine, and the same procedure as in Example 1 (1) was carried out otherwise to obtain 1,2-quinonediazidesulfonic acid ester. Table 1 shows the amount of raw material charged and the compositional analysis results of the obtained 1,2-quinonediazide sulfonic acid ester by GPC. Next, the novolak resin obtained in Example 1 (2) and the 1,2-quinonediazide sulfonic acid ester were used, and otherwise the same as in Example 1 (3), to prepare a positive resist solution. did. Then, Example 1
Similar to (3), a resist layer was formed on a silicon wafer, and a stepper was used to irradiate it with ultraviolet rays through a pattern mask for the number of exposure seconds shown in Table 1 to obtain TM of each concentration shown in Table 1.
It was developed with an aqueous solution A, rinsed with water and dried. Table 1 shows the resolution of the obtained resist pattern.

Comparative Examples 1 to 4 1,2-quinonediazide sulfonic acid was prepared by substituting 14.3 g of triethylamine with the basic catalysts shown by A to D in Table 1 and otherwise treating as in Example 1 (1). The ester was obtained. Table I shows the amounts of raw materials charged and the compositional analysis results of the obtained 1,2-quinonediazide sulfonic acid ester by GPC. Next, the novolak resin obtained in Example 1 (2) and the 1,2-quinonediazide sulfonic acid ester were used, and otherwise the same as in Example 1 (3), to prepare a positive resist solution. did. Then, Example 1
Similar to (3), a resist layer was formed on a silicon wafer, and a stepper was used to irradiate it with ultraviolet rays through a pattern mask for the number of exposure seconds shown in Table 1 to obtain TM of each concentration shown in Table 1.
It was developed with an aqueous solution A, rinsed with water and dried. Table 1 shows the resolution of the obtained resist pattern.

[0029]

[Table 1] A: 20 wt% sodium carbonate aqueous solution 95 ml B: Saturated sodium hydrogen carbonate aqueous solution 296 ml + 10 wt% sodium carbonate aqueous solution 42 ml C: 25 wt% sodium carbonate aqueous solution 20.4 g D: Saturated sodium hydrogen carbonate aqueous solution 198 ml + 10 wt% sodium carbonate 28 ml (Note) * THBP: 2,3,4,4'-tetrahydroxybenzophenone ** NQD: 1,2-naphthoquinonediazide-5-sulfonic acid chloride

Examples 5 to 8 Instead of the novolac resin obtained in Example 1 (2),
A novolak resin obtained by polycondensation using mixed cresols having a mixing ratio shown in Table 2, 66 ml of a 37% by weight aqueous formaldehyde solution and 0.04 g of oxalic acid was used, and otherwise the same as in Example 1 (3). To prepare a positive resist solution of the present invention. Then, a resist layer was formed on a silicon wafer in the same manner as in Example 1 (3), and was irradiated with ultraviolet rays through the pattern mask using a stepper for the exposure time shown in Table 2 and developed with a 2.4% by weight TMA aqueous solution. Then rinsed with water and dried. The resolution of the obtained resist pattern was high, and no development residue was observed.
The results are shown in Table 1.

[0031]

[Table 2]

[0032]

INDUSTRIAL APPLICABILITY The present invention is based on the feature that amines are used as the basic catalyst in the condensation reaction, and is compared with the case where other basic catalysts, for example, inorganic alkalis such as sodium carbonate and sodium hydrogen carbonate are used. As a result, a radiation sensitive agent for positive resist having a high proportion of tetraester in the condensation reaction product can be produced. That is technically significant for preparing a positive resist for obtaining a resist pattern having excellent developability and high resolution. Furthermore, there is an advantage that it is possible to produce a radiation sensitive agent for positive resist in which metal based on an extremely small amount of an inorganic alkali catalyst which is very difficult to purify and which affects the performance of an integrated circuit does not remain. The positive resist using the radiation sensitive agent for positive resist according to the present invention has good developability and high resolution. Further, a positive resist using the radiation sensitive agent for positive resist according to the present invention is
Sensitive to radiation such as ultraviolet rays, far ultraviolet rays, X-rays, electron beams, molecular beams, γ-rays, synchrotron radiation, and proton beams, and is suitable as a resist for integrated circuit production, particularly as a positive resist for highly integrated circuit production. It is something.

Claims (1)

[Claims] 1. Tetrahydroxybenzophenone and 1,
A method for producing a radiation-sensitive agent for positive resist, which comprises subjecting 2-quinonediazide sulfonic acid halide to a condensation reaction in the presence of amines.