JPS5877044A - Production of disk original board - Google Patents

Abstract

PURPOSE:To increase the contact intensity of a photoresist film, by producing a cross-linking reaction after coating thin a photoresist to a glass substrate or a reflecting film provided on the substrate. CONSTITUTION:A reflecting film 2 is formed on a glass substrate 1, and a photoresist is coated thin (100Angstrom ) to the film 2 to obtain a photoresist film 3a. Then a cross-linking reaction is produced at high temperatures between the films 2 and 3a. Then a photoresist layer 3b of about 1,000Angstrom is formed to perform exposure and development.

Description

[Detailed description of the invention] The present invention relates to a method for manufacturing a master disk.

A disk striker, which is formed by forming a spiral track on the disk surface using a laser beam, is usually manufactured through the following manufacturing process. First, a reflective film (21) is formed by vapor-depositing chromium that reflects laser light on the surface of the glass substrate (11), and a photoresist material of 0.1μ8 is further coated on this reflective film (2). Resist layer (3
), prebaked at 80℃, mounted on a recording device, recorded information with laser light, developed and dried, and postbaked at 100℃ to form bits into a spiral disk. The master disc was being produced (first
(see figure). FIG. 1 schematically shows a cross section of this disk master. However, when a metal film (4) made of silver is formed on the surface of the disk master produced in this way, and a nickel layer (5) is further formed on the surface by plating, a nickel replica disk is produced. (See Figure 2), because the adhesion strength between the reflective film (2) and the photoresist layer (3) is weak, the phenomenon in which the photoresist layer (3) partially peels off due to the formation of the nickel layer +51 occurs. Due to this peeling, the copy bit was not formed correctly on the surface of the replica disc, and a bulge was created in the area corresponding to the peeling. This bulge caused a dent in the surface of the disc record that was later formed. 8/N of the reproduced information was degraded.

Therefore, the reflective film and photoresist layer are still attached to the glass substrate.
In order to increase the adhesion strength of the resist layer, adhesion enhancers such as DNS have been used, but it has not been possible to obtain sufficient adhesion.

Therefore, in view of the above-mentioned points, the present invention proposes a new and effective disk master manufacturing method in which the adhesion strength of a photoresist to a glass substrate (or a reflective film on a glass substrate) is strengthened.

Hereinafter, the present invention will be explained according to an illustrative example. 6th
The figure is a process explanatory diagram of the method of this embodiment.

First, in this embodiment, as a first step, a chrome reflective film (2) is formed on the glass substrate Ill [FIG. 3(a)].

Note that this step is for forming a film that reflects the recording beam, and is not necessarily an essential step for the present invention. As a second step, the disc is dried at a high temperature of 150°C to remove moisture on the surface of the reflective film (21).As a third step, a thin layer of photoresist is applied on the surface of the reflective film (121).
X) Coating to form a photoresist film (31) [Fig. 5 (bJ). This film thickness is sufficiently thin compared to the depth of the recording pit of approximately 0.1 μm. In the fourth step, the disc is ℃ for 30 minutes to 1 hour to cause a crosslinking reaction between the reflective film (21) and the photoresist film (3a) to strengthen the adhesion strength. As a fifth step, the photoresist film (5a) is heated at room temperature. Coat a photoresist on the surface of the photoresist layer (5b
) [Fig. 3 (C1)]. In the sixth step, the disk is prebaked at 80° C. to 100° C. for about 6 hours.

As a second step, the surface of the Reisf is exposed to a recording laser beam and subjected to development processing [FIG. 3(d)].

As an eighth step, post-baking is performed at 80° C. to 100° C. for 30 minutes to 1 hour to promote drying of the disk surface and crosslinking reaction of the photoresist.

The disk subjected to the above-described process has a strong VII resistance between the photoresist layer, photoresist film, and reflective film, and peeling does not occur in the subsequent replica disk manufacturing process as in the past.

Incidentally, among the steps of this embodiment, the first, second, fifth to eighth steps are almost the same as the conventional steps, and the feature of this embodiment lies in the third and fourth steps. . That is, the present invention is characterized in that the reflective film and the photoresist are firmly bonded when the photoresist film is coated and a high temperature is applied.

Therefore, according to the present invention, since the photoresist causes a crosslinking reaction with the glass substrate or the reflective film on the glass substrate, there is no fear of peeling during replica production, and the effect is great.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view of a conventional disk master, FIG. 92 is a schematic sectional view during replica manufacturing, and FIG. 5 is a process explanatory diagram of one embodiment of the present invention. Description of main books (5a)...Photo, Resist III, (5b) -
...Photoresist layer, (1)...Glass substrate. Figure 1 21I

Claims (1)

[Claims] Yama: In a method of manufacturing a disk master in which a photoresist layer is irradiated with a laser beam and then developed to form recording bits on the disk surface, recording pits are formed one-on-one on a glass substrate or a reflective film on a glass substrate. a step of coating a photoresist that is sufficiently thin compared to the depth, and a step of causing a crosslinking reaction of the photoresist to the glass substrate or the reflective film on the glass substrate below this step; A method for manufacturing a disk master comprising the step of further applying a photoresist approximately to the depth of the recording pits at room temperature.