JPS58149041A - Positive type photoresist composition - Google Patents

Abstract

PURPOSE:To improve the adhesive strength of a resist film to its substrate, by adding epoxy resin to a positive type photoresist composition contg. a quinonediazido compound as a photosensitive agent. CONSTITUTION:Epoxy resin having 200-20,000mol.wt. is added to a positive type photoresist composition consisting of a photosensitive component contg. a quinonediazido group, an alkali-soluble resin component and a solvent. Thus, a pattern with high resolution is obtd. Without deteriorating the developability of the original positive type photoresist, and the resist pattern has remarkably improved adhesive strength to its substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to positive photoresist compositions.

Conventionally, photosensitive compositions containing a compound having a naphthoquinone diazide group or a benzoquinone diazide group have a molecular weight of 300 to 500
When irradiated with light, the quinone diacid group decomposes to form a carboxyl group, which changes the state from an alkali-insoluble state to an alkali-soluble state, which is used as a positive photoresist and a positive M15 plate. A compound containing a naphthoquinone diazide group or a benzoquinone diazide group can be obtained, for example, by combining naphthoquinone diazide sulfonic acid chloride or benzoquinone diazide sulfonic acid chloride with a low-molecular compound or high-molecular compound having a hydroxy group in the presence of a weak alkali. . Examples of low molecular weight compounds include hydroquinone, resorcinol,
Examples of polymer compounds include phenol-formaldehyde novolac resin,
Examples include cresol-formaldehyde novolak resin, polyhydroxystyrene, and the like.

In addition to this, photosensitive compositions containing these photosensitizers usually include:
Contains resin components. This is an essential component to provide a uniform and strong eyelid membrane and to withstand practical use as a photoresist or PS plate. It is also required that it can be developed with alkali. Novolac resins are suitable as such resins, and phenol-formaldehyde novolac resins and cresol-formaldehyde novolac resins are widely used in practical use. In addition, styrene-maleic anhydride copolymer, polyhydroxystyrene, and acrylic resin having a carboxyl group are used.

The above positive type photoresists generally have significantly better resolution than photocurable (negative FF1) photoresists. Taking advantage of this high resolution, it is used as an etching protective film (resist film) for photolithography when manufacturing integrated circuits such as copper-clad laminate boards for printed wiring and ICs and LSIs. Now, as integrated circuits become more highly integrated and miniaturized, patterns with a width of 1 μm are now required. However, for such fine patterns, high resolution and adhesion of the resist film to the substrate are extremely important. In other words, it is required that thin lines or notches with a corner size of about 1 .mu.m are strongly adhered to the substrate without being peeled off through the resist film development and etching steps. Conventional photoresist compositions do not always have satisfactory adhesion, and improvements have been desired.

As a result of investigation, it was discovered that the adhesion was significantly improved by adding an epoxy resin, leading to the present invention. That is, the present invention relates to a positive photoresist composition characterized in that an epoxy resin is added to a positive photoresist composition containing a quinonediazide compound as a photosensitizer. Embodiments of the present invention will be specifically described below.

As mentioned above, the positive photoresist composition used by adding the epoxy resin of the present invention has a quinone diazide group, and the quinone diazide group is decomposed by irradiation with light of 300 to 500 n%μ to produce a carboxyl group.
It includes all compositions that change from alkali-insoluble to alkali-soluble.

This composition generally comprises a photosensitizer component containing a quinonediazide group, an alkali-soluble resin component, and a solvent.

First, a photosensitizer component containing a quinonediazide group is obtained by reacting naphthoquinonediazide sulfonic acid chloride or benzoquinonediazide sulfonic acid chloride with an acid chloride and a low molecular weight metal or polymer compound having a functional group capable of a synthesis reaction. Examples of functional groups capable of condensation reaction with acid chloride include hydroxyl groups and amino groups, with hydroxyl groups being preferred. Examples of low-molecular compounds containing hydroxyl groups include hydroquinone, resorcinol, phloroglucin, 2,4-dihydroxybenzophenone,
Examples include 2,3.4-) dihydroxybenzophenone and gallic acid alkyl ester, and examples of polymeric compounds containing hydroxyl groups include phenol-formaldehyde novolak resin, cresol-formaldehyde novolak resin, and polyhydroxystyrene.

Next, regarding the alkali-soluble resin component, examples include novolac resin, styrene-maleic anhydride copolymer, polyhydroxystyrene, and acrylic resin having a carboxyl group, among which novolac resin is preferred.

Examples of novolak resins include phenol formaldehyde novolak resin and cresol formaldehyde novolak resin.

The ratio of the photosensitizer component to the alkali-soluble resin component is 1:1.
It is preferable to use it in the range of 1 to 6.

A resist solution is prepared by combining these photosensitizer components and alkali-soluble resin components in a solvent. The solvent used here is preferably one that provides an even and smooth coating film after evaporation of the solvent at an appropriate drying rate.

These include ethyl cellosolve acetate,
Methyl cellosolve acetate, ethyl cellosolve, methyl cellosolve, phtyl acetate, methyl isobutyl ketone,
Xylene, etc. are used.

that's all. Positive type, O4. Additional additives such as additional resins, plasticizers, pigments, etc. may be added to the composition.

Next, in order to improve adhesion, which is the objective of the present invention; main components,
The epoxy resin will be specifically explained. For epoxy resins, see the Encyclopedia of Polymers.
Science and Technology, vol. 6, p. 129 (
Interscience Publishing). That is, an epoxy resin is a low-molecular or high-molecular compound having two or more epoxy groups in one molecule. Among these, the epoxy resin suitable for use in the present invention has a molecular weight of 200 to 20.
．． 000. If you use something in this range,
The composition provides a composition in which a high-resolution pattern can be obtained without impairing the developability of the original positive photoresist, and the adhesion of the resist pattern to the substrate is improved.

The epoxy resin can be synthesized from epichlorohydrin and an active hydrogen compound or by oxidizing an olefin, and either method can be used.

The former synthesis method is widely used industrially, and commercially available products are also readily available (convenient for use in the present invention. Such methods include the reaction product of bisphenol A and epichlorohydrin, tetrabromobisphenol A reaction product of and shrimp chlorohydrin, reaction product of resorcin and epichlorohydrin, reaction product of phenol formaldehyde novolac resin and epichlorohydrin, reaction product of cresol-formamide novolac resin and epichlorohydrin, reaction product of P-aminophenol and epichlorohydrin, aniline and epichlorohydrin. Examples of the latter method obtained by oxidizing solenoid include epoxidized polybutadiene and epoxidized soybean oil.

The amount of the epoxy resin added is preferably within a range that does not significantly change the photosensitive characteristics of the photoresist. The amount added varies depending on the type and molecular weight of the epoxy resin used, but in general, if the photosensitizer component, alkali-soluble resin component, and additional additives are included, it is 1 to 30% of the total of the components. Good results can be obtained when used within the range of .

The photoresist composition of the present invention described above can be used for large-scale integrated circuits having patterns of about 1 μm by taking advantage of its high resolution and very good adhesion to the substrate. Other shadow mask processing, C
Color filter processing for CD, printed wiring processing, PS
It can be used for various purposes including lithographic printing.

EXAMPLES The present invention will be specifically explained below with reference to Examples, but of course the present invention is not limited to these Examples.

Example 1 Forkified Chestnut (Kyu) Crack J The above composition was passed through a 0.2μ scale filter to prepare a resist solution. This was applied to a silicon wafer cleaned by a conventional method using a spin coating machine at 4000 rpm. The resulting film thickness was 0.86 μm. This was placed in a clean oven at 80°C and dried for 30 minutes.

Then, using a contact mask aligner using a 350 W ultra-high pressure mercury lamp as a light source, exposure was performed for 8 seconds through a mask having a minimum line of 1.0 μm. This is 0.25 N
It was immersed in an aqueous potassium hydroxide solution and developed for 2 minutes. After development, the pattern was observed using a microscope, and it was found that a 1.0 μm pattern was formed without peeling, indicating good adhesion. On the other hand, for comparison, a composition without the addition of epoxy resin was similarly patterned with Kaoru, but 4μ
Partial peeling of the line below the thickness was observed.

Example 2 The above composition was passed through a 0.2μ inertia filter, and applied, exposed and developed in the same manner as in Example 1.
．． The Oswa pattern was formed on the wafer without peeling and had good adhesion.

Example 3 In Example I, the epoxy resin was
011 (manufactured by Sumitomo Chemical Co., Ltd.) except that it was changed to 011 (manufactured by Sumitomo Chemical Industry ■). As a result, 1.0μ
The steel pattern was formed on the wafer without peeling, and the adhesion was good.

Example 4 The epoxy resin in Example 1 was changed to Sumiepoxy ESCN.
-220L (manufactured by Sumitomo Chemical Co., Ltd.) was used, but the experiment was carried out in the same manner. As a result, the pattern at the 1.0 μm corner was formed on the first wafer without peeling, and the adhesion was good.

Claims (1)

[Claims] A positive photoresist composition comprising an epoxy resin added to a positive photoresist composition containing a quinonediazide compound as a photosensitizer.