JPS60246040A - Production of optical disk - Google Patents

Abstract

PURPOSE:To prevent deformation of fine grooves for tracking and to improve weatherability by depositing TeO2 on the surface of an optical recording layer formed on the surface of a substrate in a vacuum. CONSTITUTION:An optical disk permits information recording at high density when a laser beam 4 is irradiated via a disk substrate 1 to the optical recording layer 2 to change the phase of the layer 2. The recorded information is read out by detecting the change of the quantity of the laser beam reflected from the phase-changed part. The layer 2 is deposited in a vacuum on the groove forming surface of the substrate 1 on which the fine grooves for tracking are formed to manufacture the optical disk. TeO2 is then deposited in a vacuum on the surface of the layer 2 to form an inert layer 3 for protecting the layer 2. The deformation of the fine grooves for tracking is thus prevented without heating the substrate 1 to a high temp. The weatherability of the disk is improved as well.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of manufacturing an optical disk having an inactive layer such as an oxide layer on an optical recording medium.

2. Description of the Related Art Optical disks are recording media for recording and reproducing various types of information such as images in real time using laser light, and have recently attracted particular attention as large-capacity, high-density memories.

Here, the optical disc is constructed, for example, as shown in Japanese Patent Laid-Open No. 59-2245 and FIG. In Fig. 2, reference numeral 1 denotes a disk-shaped disk substrate made of transparent synthetic resin with excellent heat resistance, and its surface has a track pitch of, for example, 1.5 to 3 μm and a depth of 500 μm. ~1
000 minute grooves for tracking are provided. Reference numeral 2 denotes an optical/recording layer formed on the surface of the disk substrate 1 on the side where the grooves are provided.
It is composed of a Te film of a thousand A. Reference numeral 3 denotes an inert layer formed on the surface of the optical recording layer 2 to protect the optical recording layer 2. The optical disc constructed in this manner is made of, for example, a TeO2 film. By irradiating the optical recording layer 2 with the laser beam 4 through the optical recording layer 2, it is possible to change the phase of the optical recording layer 2 and record high-density information, and also to change the amount of reflected light of the laser beam with respect to the phase change part. The recorded information can be read by detecting the . An optical disc having such a configuration is manufactured, for example, by a method as shown in FIG. First, in the first step 5, a synthetic resin having light transmittance and excellent heat resistance is used as a material, and the surface is coated with a depth of 500 to 100 Ω at a pitch of, for example, 1.5 to 3 μm.
A disk-shaped disk substrate 1 having fine grooves used for A" degree tracking is made. In this case, the fine grooves are made by a method such as etching the surface of the disk substrate 1.Next. In the second step 6, Te1ii as the optical recording layer 2 is formed on the groove forming surface of the disk substrate 1 by vapor deposition or splattering of Te while the disk substrate 1 is housed in a vacuum container. Next, in the third step 7, the disk substrate 1 on which the Te layer has been formed is removed from the engineering container and then heated in air in an oxidizing atmosphere.
The surface of Te/il is oxidized to form an inactive layer 3 for protecting the optical recording layer 2.

Problems to be Solved by the Invention However, in the method for manufacturing an optical disc described above, the pTe layer is heated in an oxidizing atmosphere by heating the disc substrate 1 on which the Te layer as the optical recording layer 2 is formed. By oxidizing the surface to TeO2, the cine-active N
However, when heat treatment is applied to the synthetic resin disk substrate 1, the fine grooves formed on the surface of the disk substrate 1 are deformed. On the other hand, when low-temperature oxidation is performed to prevent groove deformation, there is a problem in that the time required for the oxidation treatment becomes longer.

Means for Solving the Problems Therefore, the method for manufacturing an optical disc according to the present invention is to apply T e 02 to the surface of an optical recording layer formed on the surface of an optical disc substrate using a method such as vacuum evaporation, spooling, or a-cuttering. By directly depositing it, an inactive layer for protecting the optical recording R is formed.

For this reason, in the optical disc manufacturing method according to the present invention, since the oxide is directly deposited on the surface of the optical recording layer, there is no need for a heat treatment process applied to the disc substrate. This prevents thermal deformation of the fine grooves formed on the surface of the disk substrate. In this case, the shape of the fine tracking grooves formed on the surface of the disk substrate greatly affects the characteristics of information recording and reading by the laser beam, so preventing the thermal deformation described above is particularly important. Become something. In addition, when directly depositing an inert layer such as an oxide, the inert layer can be obtained by simply changing the deposition source or target without breaking the vacuum during the optical recording layer deposition process. Therefore, the weather resistance of the optical recording layer is significantly improved, and the time required for manufacturing is also significantly shortened.

Embodiment FIG. 1 is a process diagram showing an embodiment of the method for manufacturing an optical disc according to the present invention, and the same parts as in FIG. 3 are indicated using the same symbols. In the figure, 8 is a guard used to protect the optical recording layer. This step is for forming the I layer, and is a substitute for the third step 7 in FIG. And this Ho W! In the step 8 of forming kM, the vacuum atmosphere used in the step 6 of forming the optical recording layer 6 is utilized. In other words, Te for forming an optical recording layer and TeO2 for forming a protective layer are prepared as an evaporation source or a snow ξ sagging source, and first, T e is An optical recording layer is formed by scattering. Next, without breaking the vacuum atmosphere 9, move the shutter to close T e (ljII and Te0
24JJ, to open Ij and scatter TeO2 °
Thus, a protective layer of Te01 is formed on the optical recording layer of Te. When the thickness of the insulation layer made of TeO2 reaches a desired value, the scattering is stopped and the vacuum atmosphere is broken and the disk substrate is taken out to complete the process.

Here, heat is also applied during the formation of the optical recording layer and the protective layer by vacuum deposition or snogging, but the heat in this process does not deform the minute grooves provided on the disk substrate. Not enough. Furthermore, when an inert layer is provided by depositing T e 02 as an oxide, the resulting inert layer is lower than when the TeO□ layer is obtained by thermal oxidation in an oxidizing atmosphere. Since it is dense, weather resistance is greatly improved.

Furthermore, by performing the deposition of the optical recording layer and the deposition of the inert layer in the same vacuum chamber, by changing the evaporation source or target, or by selectively using a shutter,
Manufacturing is easy and can be done in a short time.

As described in detail of the invention, the method for manufacturing an optical disk according to the present invention includes forming a TeO2 film as an inactive layer on the surface of an optical recording layer by using methods such as vapor deposition and sputtering. Since the disk substrate is made of a metal material, the disk substrate is not heated to a high temperature, and accordingly, the fine tracking grooves formed on the surface of the disk substrate are prevented from being deformed. Furthermore, when an inactive layer is formed by scattering TeO2, the film quality is denser than when it is obtained by thermal oxidation, so weather resistance is significantly improved. Furthermore.

Since the formation of the TeO2 film can be processed in a vacuum atmosphere for forming the optical recording layer, it can be manufactured easily and in a short time without using special equipment. Has excellent effects.

[Brief explanation of drawings]

Fig. 1 is a process diagram for explaining the method of manufacturing an optical disc according to the present invention, Fig. 2 is a sectional view of the main part of the optical disc, and Fig.
The figure is a process diagram showing a conventional optical disc manufacturing method. 5... Disc substrate manufacturing process, 6... Optical recording layer manufacturing process, 8... Inactive layer manufacturing process. Figure 1

Claims (2)

[Claims] (1) A first step of depositing an optical recording layer on the groove forming surface of a disk substrate having fine tracking grooves on one surface in a vacuum, and an optical record made by this first step. a second step of forming an inactive layer for protecting the optical recording layer by depositing TeO2 on the surface of the layer in vacuum; (2) The method for manufacturing an optical disk according to claim 1, wherein the first step and the second step are processed in the same vacuum atmosphere.