JPH0417137A - Manufacture of stamper for optical disk - Google Patents

Abstract

PURPOSE:To implement exfoliation processing of a stamper and removal of resist at once in a short time with a simple device with almost no damage to the master stamper by allowing an ultraviolet ray (UV) to radiate to the master stamper under the existence of ozone. CONSTITUTION:At least one of removal of resident photo resist from a master stamper, exfoliation processing of the master stamper and exfoliation processing of mother stamper is implemented under the presence of ozone through ultraviolet ray radiation. The resist resident on the surface of the stamper becomes a chemical compound with a low molecular weight by the UV radiation, and it is oxidized and decomposed by ozone. Then the Ni surface from which resist removed is oxidized by ozone and exfoliation of a copy stamper in the electrocasting processing is facilitated. Since the removal of resist and the exfoliation processing are implemented at once with a simple device, the processing time is very less and a damage to the stamper is less, then the quality is improved.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a method for manufacturing a stamper for optical disks.
In particular, when manufacturing a copy stamper from a master stamper via a mother stamper by electroforming, the pretreatment of the master stamper and mother stamper is easy, and the master stamper is subjected to resist and peeling treatment, and the mother stamper is - relates to a method for manufacturing an optical disc stamper that can be easily peeled off.

<Prior Art> A stamper for an optical disc is manufactured from a master stamper to a copy stamper via a mother stamper.

In this manufacturing process, the master stamper is subjected to electroforming after the resist remaining on the surface is removed and a peeling process is performed, and the mother stamper is subjected to a peeling process.

Conventionally, in these processes, the resist is generally removed by plasma ashing, electrolytic degreasing, etc., and the stripping process usually involves immersion in sulfamic acid or citric acid, and then immersion in potassium dichromate. is being processed.

<Problems to be Solved by the Invention> However, in these conventional processing methods, in the case of resist removal, the ashing method requires expensive equipment, and the electrolytic degreasing method requires complicated processing operations.
Furthermore, both processing methods require a large space;
This causes an increase in costs. Furthermore, since potassium dichromate (hexavalent chromium) is used in the stripping process, wastewater treatment is required to prevent pollution.

Therefore, the present invention has been devised to remove the resist and peel off the stamper at once using a relatively simple device in a short period of time, as well as to remove the stamper for optical discs, which does not require wastewater treatment and does not take up much space in terms of equipment. The purpose is to provide a manufacturing method.

<Means for Solving the Problems> In order to solve the above-mentioned problems and obtain a high-quality copy stamper, the present invention is directed to removing the resist from the master stamper, peeling off the master stamper, and peeling off the mother stamper. As a result of extensive research into methods that can perform processing efficiently, we have discovered that by irradiating the master stamper with ultraviolet (UV) light in the presence of ozone, the resist can be removed with almost no damage to the master stamper. We have found that peeling treatment can be performed and have arrived at the present invention.

That is, in order to solve the above-mentioned problems, the present invention provides a method for manufacturing a stamper for an optical disk, in which resist removal from a master stamper, a peeling process for a master stamper, and/or a peeling process for a mother stamper are performed using ozone. The present invention provides a method for producing a stamper for an optical disc, which is characterized in that the process is carried out by irradiating ultraviolet rays in the presence of a stamper.

It is preferable that the treatment temperature is 80°C or higher.

Further, the ozone concentration in the treatment is 0. It is preferable that it is 1% or more.

Furthermore, it is preferable that the processing time is 30 seconds or more.

Hereinafter, the present invention will be described in detail according to the embodiments of the present invention shown in FIGS. 1(A) to 1(E).

First, a photoresist is applied to the surface of a glass substrate, exposed to laser light (not shown), and then developed to form a photoresist on the surface of the glass substrate 1, as shown in FIG. A glass master 4 having desired groups and bits 3 formed by the resist 2 is produced. Here, the glass substrate, photoresist, exposure, development conditions, etc. used may be conventional ones and are not particularly limited.

Next, the glass master 4 is made conductive by nickel sputtering, electroless nickel plating, etc., and then electroformed to form a master stamper 5 as shown in FIG. 1(B). The master stamper 5 is peeled off from the glass substrate, and then the photoresist 2 is removed to obtain the master stamper 5 shown in FIG. 1(C).

The method of the present invention involves removing residual photoresist from the master stamper and stripping the master stamper!
At least one of the IIIA process and the mother stamper peeling process described below is performed by irradiating ultraviolet rays in the presence of ozone.

This treatment by irradiating ultraviolet rays in the presence of ozone can be carried out by directly treating the master stamper and mother stamper obtained by electroforming in a commercially available heating type UV/ozone generator.

The heating temperature is preferably 80 to 250°C in processing the master stamper, since the resist can be sufficiently removed and the surface of the master stamper will not be damaged and a high-quality copy stamper can be obtained. 12
0~180℃ is good. Also, in the mother stamper treatment, the temperature is usually 80 to 250°C, preferably 12°C.
0 to 180°C is good.

The ozone concentration is usually 0.1% or more.

Furthermore, the processing time may generally be 30 seconds or more.

The thus obtained master stanbar is washed with pure water and then subjected to electroforming in the same manner as in FIG. -6 is produced in plurality, for example, five.

In producing the plurality of mother stampers 6, the mother stamper formed by the master stamper is obtained by peeling off the master stamper.
Process A is carried out by irradiating ultraviolet rays in the presence of ozone.

After washing the prepared mother stampers with pure water, they are subjected to electroforming as shown in FIG. 1(B), and a copy stamper 7 as shown in FIG. 1(E) is formed. Multiple pieces are made.

A desired optical disc can be manufactured using the copy stamper thus obtained.

In addition, in electroforming, a circular electrode is used to conduct electricity between a conductive glass substrate, a master stamper, and a mother stamper. At this time, when the circular electrode is irradiated with ultraviolet rays in the presence of ozone, the resulting nickel plate and Improves peeling.

Effect> In the method of the present invention, the resist present on the surface of the stand bar is converted into a low molecular weight compound by UV irradiation, and then oxidized and decomposed by ozone. Next, the Ni surface free of resist is oxidized by ozone, and it is thought that the electroformed copy stamper can be easily peeled off.

<Examples> Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples of the present invention.

(Example 1) After irradiating a glass substrate coated with a resist with a laser beam, it is developed to dissolve the portion irradiated with the laser beam,
Dry. Next, nickel sputtering was performed to obtain a conductive glass substrate (glass master).

This glass master was electroformed with nickel to form a master stamper.

This was immersed in acetone for 5 minutes to remove a portion of the resist, washed with water, and then dried in isopropanol (TPA) steam. Treatment was performed at 150° C. for 5 minutes while flowing min (ozone concentration: 1%). The master stamper treated with UV/ozone cleaner was washed with water, then dried with IPA, and nickel electroforming was performed under the same conditions as above to form a mother stamper.

The mother stamper formed by electroforming could be easily peeled off from the master stamper.

The obtained mother stamper was washed with water, dried with IPA, treated with UV/ozone cleaner at 150'C for 5 minutes in the same way as the master stamper, and then nickel electroformed to form a stamp bar. .

The stamp bar formed by electroforming could be easily peeled off from the mother stamper.

An optical disc was manufactured using the stand bar thus obtained.

This optical disc was subjected to a performance evaluation test, the bite error rate (BER), which is a measure of product quality, was measured, and if it was peeled using conventional citric acid/potassium dichromate. When compared with that of the optical disc obtained by II processing, it showed a small byte error rate.

(Comparative Example 1) A master stamper obtained in the same manner as in Example 1 was
After immersing it in acetone for 5 minutes to remove a portion of the resist, it was washed with water. Then, after drying in IPA vapor,
Heat treatment was performed in air at 150°C for 5 minutes. Thereafter, it was washed with water, dried with IPA, and nickel electroformed.

After nickel electroforming, the mother stamper that was supposed to be obtained from the master stamper could not be easily peeled off, and when it was forcibly peeled off, it was deformed and could not be used as a copy stamper.

<Effects of the Invention> According to the method of the present invention, resist removal and peeling treatment,
Since the process can be carried out all at once using relatively simple equipment, the processing time is very short, and since there is little damage to the stamper, a copy stamper of excellent quality can be obtained. Furthermore, it does not require wastewater treatment and does not take up much space in terms of equipment, contributing to improved productivity.

[Brief explanation of drawings]

FIGS. 1(A) to (E) illustrate the present invention. FIG. Explanation of symbols 1...Glass substrate, 2...Photoresist, 3...Group and pit, 4...Glass Master 5...Master stamper 6...Mother stamper 7...Copy standby implementation

Claims (1)

[Scope of Claims] (1) In the method for manufacturing a stamper for an optical disc, the resist removal from the master stamper, the master stamper peeling process, and/or the mother stamper peeling process are performed by irradiating ultraviolet rays in the presence of ozone. A method for manufacturing an optical disc stamper characterized by: (2) The method for manufacturing an optical disc stamper according to claim 1, wherein the processing temperature is 80°C or higher. (3) The method for producing an optical disc manufacturing stamper according to claim 1 or 2, wherein the ozone concentration in the treatment is 0.1% or more. (4) The method for manufacturing an optical disc stamper according to any one of claims 1 to 3, wherein the processing time is 30 seconds or more.