JPH02281932A - Manufacture of stamper for optical memory - Google Patents

Abstract

PURPOSE:To control generation of unevenness in a development, by a method wherein a far ultraviolet irradiation process of the surface of a glass board is performed as a preprocess of a forming process of a photoresist. CONSTITUTION:Wet abrasion of the surface of a glass board is performed and then rubbing washing, for which pure water is used to remove an abrasive grain, is performed. Then the glass board is dried by a spin drying or baking (150 deg.C) after supersonic washing of the same with the pure water or the same is dried similarly by the baking after steam washing of the same, for which isopropyl alcohol is used. Then dry washing by far ultraviolet irradiation is performed. Hereupon, hours required for treatment of the glass board and hours for which the same is left as it is (extending from far ultraviolet treatment up to coating of a resist and from the coating of the resist up to developing) are closely connected with an effect of the far ultraviolet irradiation. It is preferable to make the hours for which the same is left as it is fall within one hour to materialize sufficiently the effect of the far ultraviolet irradiation. With this construction, a developing mark is controlled and yield in a manufacturing process of a stamper for optical memory can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for cleaning a glass substrate used in the manufacturing process of a stand bar, which is a mold used in manufacturing an optical memory disk substrate.

[Prior Art 1 The manufacturing process of a conventional optical memory stamper is as described below.

First, the surface of the glass substrate (stamper forming surface) is subjected to optical research, followed by precision cleaning using water or organic solvent.Next, photoresist is coated on the glass substrate to a specified thickness, prebatered, and after cooling, a specified Exposure is performed using a modulated laser beam, and after development and post baking, a fine resist pattern is obtained. This resist pattern is subjected to conductive treatment to form an electroformed film, the resist pattern is transferred to the surface of the electroformed film, and the electroformed film is shaped to obtain a stand bar.

Problems to be solved by the invention E] However, in the standby manufacturing process that is the prior art described above,
Since photolithography is performed using an extremely thin resist film of approximately 0.1 um, it is extremely difficult to uniformly develop the entire surface of the resist during the development process, which may result in uneven development. In this case, this was directly transferred to the surface of the electroformed film, ie, there was a problem in that the yield was reduced due to poor appearance of the standby surface. especially,
When V-shaped grooves are formed as guide grooves, development is performed only part way through the resist film, which is so-called halftone development, so that uneven development is more likely to occur. One approach to solving this problem is to improve the developing device. In other words, the idea is to improve the uniformity of development and eliminate uneven development by devising the shape of the nozzle that discharges a chemical solution such as developer and the arrangement of the nozzle with respect to the glass substrate. When we look at development by dividing it temporally and spatially, the entire surface of the resist is not developed under exactly the same conditions.In other words, there is a natural limit to the approach from the development equipment side, and the standby standby for optical memory The development process of the manufacturing process is
Particularly when halftone development is performed, the aforementioned microscopic non-uniformity of the development process has a large influence, and the defective rate due to development unevenness is high. SUMMARY OF THE INVENTION The present invention is intended to solve these problems, and its purpose is to improve the yield in the manufacturing process of optical memory standbers.

[Means to solve the problem]

The method for manufacturing an optical memory standby of the present invention involves forming a photoresist film on a glass substrate, exposing the photoresist film to light and developing it, and applying conductorization and electroforming treatment to the resulting resist pattern. In the manufacturing process of an optical memory standby in which a standby is manufactured by obtaining a cast film and shaping the electroformed film, a step of irradiating the surface of the glass substrate with deep ultraviolet rays is performed as a pre-step of the step of forming the photoresist film. shall be.

[Function] Far ultraviolet irradiation treatment is generally performed for the purpose of removing organic contamination from the substrate surface.Mechanistically, organic substances are decomposed by the energy of far ultraviolet rays and the oxidizing power of ozone generated by far ultraviolet rays. It is something that

[Example] The present invention will be explained below based on examples.

The surface of the glass substrate is wet studied and then scrubbed with pure water to remove the research abrasive particles. Next, the glass substrate was ultrasonically cleaned with pure water, spin-dried, and baked (1
50°C) or steam cleaning using isopropyl alcohol, followed by dry cleaning by baking and then dry cleaning by far ultraviolet irradiation.The cleaning equipment used is MUS-2 sold by Mitsui & Co.
00H type was used. The distance between the glass substrate and the mercury lamp was 10 mm. Processing time and standing time (from far ultraviolet treatment to resist coating and from resist coating to development)
Although this is closely related to the effect of far ultraviolet irradiation, experiments were conducted under various conditions as shown in Table 1. However, since the number of experiments would be enormous, the standing time from resist application to development was fixed at 3 hours as a common sense time. After the cleaning process using far ultraviolet irradiation, the same process as the conventional process was performed to produce a stand bar. Obtained standby developing tube 1
The yield regarding surface unevenness was as shown in Table 2.

In addition, the yield rate of the conventional manufacturing tube for optical disk standbers is 5.
It is 0%. From the results shown in Table 2, it can be seen that far ultraviolet irradiation is effective against uneven development. However, the effect decreases as the standing time increases. In order for the effect of far ultraviolet irradiation to be fully manifested, it is desirable to leave it for less than 1 hour, and the treatment time should not be more than 3 minutes, as the effect is not fully exhibited at 1 minute. desirable. The results in Table 2 are the results when the standing time from resist application to development was fixed at 3 hours, but in reality this time varies. However, even in that case, it is sufficient to consider according to Table 2, and it is desirable to keep the standing time as short as possible. In the present invention, far ultraviolet irradiation is applied to the surface of the glass substrate, and the photoresist surface to be developed is Although it is not applied to the surface of the photoresist, the fact that uneven development has been eliminated means that the glass substrate surface was cleaned by far ultraviolet irradiation, which resulted in uniform development on the photoresist surface. . This is because the photoresist film thickness is extremely thin at about 0.1 μm, and it is thought that the surface properties of the glass substrate affect the photoresist surface.

[Effects of the Invention] As described above, according to the present invention, in the manufacturing process of an optical memory stamper, the occurrence of uneven development can be prevented by performing a deep ultraviolet irradiation process on the glass substrate surface as a pre-process of the photoresist film formation process. This has the effect of improving the yield in the developing process since no defects in appearance occur.

that's all Applicant: Seiko Epson Corporation

Claims (1)

[Claims] A photoresist film is formed on a glass substrate, the photoresist film is exposed and developed, the resulting resist pattern is made conductive and electroformed to obtain an electroformed film, and the electroformed film is shaped. A method for manufacturing a stamper for an optical memory, characterized in that a step of irradiating a glass substrate surface with deep ultraviolet rays is performed as a pre-step of the step of forming the photoresist film, in the step of manufacturing a stamper for an optical memory.