JPH02245754A - Positive type resist composition - Google Patents

Abstract

PURPOSE:To obtain a positive type resist compsn. having superior resolution by incorporating novolak resin and one or more kinds of quinonediazidosulfonic esters of a specified phenol compd. CONSTITUTION:Novolak resin and one or more kinds of quinonediazidosulfonic esters of a phenol compd. represented by formula I are incorporated. The esters may be produced by condensing naphthoquinonediazidosulfonic acid halide and benzoquinonediazidosulfonic acid halide with the phenol compd. in the presence of a weak alkali such as sodium carbonate. A positive type resist compsn. having superior resolution and not causing the increase of development residue or other problem is obtd.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a resist composition with a high r value @ <Prior Art and Problems of the Invention> A composition consisting of a compound having a quinonediazide group and a novolak resin The material can be used as a positive resist by utilizing the fact that the quinone diazide group decomposes to produce a carboxyl group upon irradiation with light of 800 to 5 Q Q nm, thereby changing from an alkali-insoluble state to an alkali-soluble state.

This positive type resist has a feature that its resolution is significantly superior to that of a negative type resist, and is used in the production of integrated circuits such as electronic circuits and LSIs.

In recent years, integrated circuits have become increasingly finer due to higher integration.
Submicron pattern formation is now required. As a result, even better resolution (higher γ value) is required for positive resists.

However, in a resist material made of a quinonediazide compound and a novolac resin, there is a limit to the improvement of the r value with conventional combinations of materials.

For example, in order to improve the r value, it is possible to increase the amount of the quinonediazide compound.

However, increasing the amount of quinonediazide compound
There are serious drawbacks such as a decrease in sensitivity and an increase in development residue.

Therefore, there was a limit to the improvement of the r value.

An object of the present invention is to provide a positive resist composition with a high r value.

The present inventors have completed the present invention by discovering that the r value can be significantly improved by using a quinonediazide sulfate ester of a polyhydric phenol compound having a specific structure.

<Means for Solving the Problems> The present invention is a positive resist composition containing a novolac resin and one or two or more parts of a quinonediazide sulfonic acid ester of a phenol compound represented by the following formula.

A known method can be used to produce the quinonediazide sulfonic acid ester of the above-mentioned phenol compound. For example, it can be obtained by condensing naphthoquinonediazide sulfonic acid halide or benzoquinonediazide sulfonic acid halide with the above-mentioned phenol compound in the presence of a weak alkali such as soda carbonate. It is preferable to carry out the reaction under conditions such that the content of the tetraester is 50% by weight or more in the ester obtained by this reaction.

In the present invention, the above-mentioned quinonediazide sulfonic acid ester may be used in one type or in two types.

Quinonediazide sulfonic acid esters of other polyhydric phenol compounds may be added to the compositions of the present invention. Other polyhydric phenol compounds include hydroquinone, resorcinol, phloroglycin, 2.4-dihydroxybenzophenone, 2.8.4-trihydroxybenzophenone,
2.8,8.4-tetrahydroxybenzophenone, 2
．． 8,4.4'-tetrahydroxybenzophenone, 2
．． Tetrahydroxybenzophenones such as 2',4.4'-tetrahydroxybenzophenone, 2,8.8'
, 4'-pentahydroxybenzophenone, 2, 8
, 8', 4, 5'-pentahydroxybenzophenones such as pentahydroxybenzophenone, gallic acid alkyl esters, and the like.

The novolak resin used in the present invention is obtained by addition-condensation reaction of phenols and formaldehyde. Specific examples of phenols used in the production of novolac resins include phenol, cresol, xylenol, ethylphenol, trimethylphenol, propylphenol, butylphenol, dihydroxybenzene, naphthols, and the like. These phenols can be used alone or in combination. As the formaldehyde to be subjected to an addition condensation reaction with phenols, an aqueous formaldehyde solution (formalin) or paraformaldehyde is used. In particular, formalin 8796 is industrially mass-produced and is convenient. The addition condensation reaction between phenols and formaldehyde is carried out according to a conventional method. The reaction is usually carried out at 60-120°C for 2-80 hours.

As the catalyst, organic or inorganic acids, divalent metal salts, etc. are used. Specific examples include oxalic acid, hydrochloric acid, sulfuric acid, perchloric acid,
Examples include p-toluenesulfonic acid, trichloroacetic acid, phosphoric acid, formic acid, zinc acetate, and magnesium acetate.

Further, the reaction may be carried out in bulk or an appropriate solvent may be used.

In the present invention, the amount of the quinonediazide sulfonic acid ester component added is preferably in the range of 15 to 60% by weight in the total solid content of the resist composition.

The resist solution is prepared by mixing and dissolving quinonediazide sulfonic acid ester and novolak resin in a solvent.

The solvent used should preferably have an appropriate drying rate and evaporate to give a uniform and smooth coating film.

Examples of such solvents include ethyl cellosolve acetate, methyl cellosolve acetate, engineered methyl cellosolve, methyl cellosolve, propylene glycol, monomethyl ether acetate, butyl acetate, methyl isobutyl ketone, xylene, and the like. The resist composition obtained by the above method may further contain a small amount of a resin, a dye, etc. as an additive, if necessary.

<Effects of the Invention> The positive resist composition of the present invention has a high r value. Further, there are no problems such as an increase in development residue.

<Examples> Next, the present invention will be described in more detail with reference to Examples, but the present invention is not limited by these Examples.

Synthesis Example 1 A compound represented by the following formula (1) was placed in a Mitsuro flask with an internal volume of 300 d at 5.20F and naphthoquinone-(1,2
)-diazide-(2)-5-sulfonic acid chloride at 20
．． 91', (reaction molar ratio 1:8.9), dioxane 2
After adding 621, it was stirred to completely dissolve it. after that,
While stirring, immerse the flask in a water bath to bring the reaction temperature to 2.
Controlled at 0-25℃, triethylane 8.6
8P was added dropwise over 80 minutes using a dropping funnel. Thereafter, stirring was continued for 4 hours while maintaining the reaction temperature at 20-25°C.

After the reaction, the mixture was charged into ion-exchanged water, filtered, and dried to obtain radiation-sensitive component B.

Synthesis Example 2 2.8°4.4
A radiation-sensitive component was obtained in the same manner as in Synthesis Example 1 except that '-tetrahydroxybenzophenone was used. The obtained radiation-sensitive component is designated as C.

Synthesis Example 8 Instead of the compound represented by formula (1), 2°8.4-
Trihydroxybenzophenone is converted into naphthoquinone (1,
The radiation-sensitive component was stirred in the same manner as in Synthesis Example I, except that the molar ratio with 2)-diazide-(2)-5-sulfonic acid chloride was 1:2.8.

Examples and Comparative Examples The radiation-sensitive component obtained in the synthesis example was mixed with a novolac resin in the composition shown in Table 1 (ethyl cellosolve acetate).
-48 parts to prepare a resist solution. The prepared resist solution was passed through a 0.2 μm Teflon filter to prepare a resist solution. This was applied to a silicon wafer cleaned by a conventional method using a spin coating machine.
．． It was applied to a thickness of 8μ. Next, this silicon wafer
It was baked on a hot plate at 00°C for 60 seconds. Next, this wafer was exposed to a reduction projection exposure machine (GC, Company A DSW480ONA=0.
28), the exposure amount was changed stepwise.

A positive pattern was obtained by developing this for 1 minute with a developer 5OPD manufactured by Sumitomo Chemical Co., Ltd.

Next, the normalized film thickness (=residual film thickness/
(initial film thickness) was plotted, its slope θ was determined, and ian θ was taken as the r value.

The results are shown in Table 1.

Table-! *Novolac resin Metacresol/paracresol; 7/8 Cresol/formalin = 110.8 Reflux using Shella acid catalyst at a molar ratio of The weight obtained by reacting Weight average molecular weight 9800 (polystyrene conversion) novolac resin.

(Margin below)

Claims (1)

[Scope of Claims] A positive resist composition containing a novolac resin and one or more quinonediazide sulfonic acid esters of phenol compounds represented by the following formula. ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I)