JPS601636A - Production of pregroup stamper for optical disk - Google Patents

Abstract

PURPOSE:To obtain a metallic stamper having uniform thickness by forming a recess part corresponding to a guide group of an optical disk on the resist film on a glass substrate to obtain a source disk and then vapor depositing a metallic thin film which can be easily stripped and then a metallic thick film on the resist of the source disk. CONSTITUTION:A positive resist is coated on the surface of a glass substrate, and a laser beam is irradiated to the resist to draw many concentric circle. Then the glass substate undergoes the development processing to obtain a source disk 2 having a recess part corresponding to a guide group of an optical disk. The disk 2 is attached to the lower side surface of a turntable 3 with the pattern surface turned down. Then a crucible 4 containing Cr within a crucible chamber is heated up to peform vapor deposition of a Cr thin film. Then Ni is vapor deposited thick on the Cr film from another crucible 4. The glass substrate is taken out of the crucible chamber and a metallic layer is removed from the substrate. In such a way, the thicknes control is facilitated for the metallic layer. Thus a metallic stamper having a uniform thickness is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a method for manufacturing a pre-group stamper for optical discs.

A conventional optical disc has a guide group for positioning a laser beam to irradiate a recording layer.

To manufacture such optical discs, a metal film stamper having protrusions corresponding to the guide groups is used.
This was pressed onto plastic to form a group of four people, and then a thin metal recording layer was deposited on top.

Such a stamper usually coats a glass disk with a positive resist, exposes it to a laser beam, and forms a latent image by drawing a large number of concentric circles with a width of about 0.7 μm on the resist.
The unexposed resist is washed out with a developer, and a metal that is easily peeled from the resist, such as silver or chromium, is deposited on this to a thickness of about 0.1 μm, and conventionally, nickel is plated in an aqueous solution to a thickness of 0.3 μm. A thick nickel film is electrodeposited and peeled off from the resist. Since such a stamper manufacturing method involves aqueous solution treatment, the operation is complicated and the nickel film thickness cannot be sufficiently controlled.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a method for manufacturing a pregroup stamper that overcomes the above-mentioned drawbacks.

Structure of the Invention The above object of the present invention is to expose and develop a resist film with a laser beam to form a master disc by providing recessed portions corresponding to the ID groups of an optical disc, and to easily peel off the resist film on the master disc. After a thin metal film is first deposited, a thick metal film is deposited on top of this thin film, and these metal films are removed from the resist to form a stand/f with protrusions corresponding to the guide groups of the optical disc. do. This can be achieved by the manufacturing method of Deli Group Stanno 7 for optical discs, which is characterized in that a thick metal film is formed by vapor deposition.

Example: Sibley, AZ13 on a glass substrate with a diameter of 30 crn.
50 is applied to a thickness of 0.07 μm, this resist is exposed to a laser beam with a diameter of 0.7 μm to draw a large number of concentric circles, and developed with a developer to form the convex portion of Stan 9. A master disk was formed with a recess corresponding to the .

In the upper part of the vacuum evaporation apparatus 1 shown in FIG. 1, the master 2 is attached to the lower surface of the turntable 3 with the pattern side facing downward, a crucible 4 with a crucible chamber is placed at the bottom, and a slit 6 with a shutter 5 is placed between the master 2 and the turntable 3. The crucible was placed opposite the patterned surface of the master 2, and the start and end of vapor deposition was controlled by heating the crucible and opening and closing the shutter. Chromium and nickel are separately put into two crucibles 4, and the apparatus 1 is heated to lXl0 in advance.
While exhausting to -6 Torr and rotating the master disc 2 at 20 Orpm, first heat the chromium crucible 4 to deposit chromium onto the master disc, then heat the nickel crucible 4 to deposit 0.3 m thick nickel. The chromium-nickel film thus obtained was deposited to produce a stamper with a thickness of 0.3 cm.

Effects of the Invention According to the present invention, a metal film is formed only by vacuum evaporation on a master disk provided with recesses corresponding to the protruding lines of the stamper, so that the manufacturing process of the stamper can be simplified, and the metal The film thickness can be better controlled.

[Brief explanation of the drawing]

Figure 1 is a sectional view of a vacuum evaporation apparatus for carrying out the method of the present invention. 1... Vacuum deposition device, 2... Master, 3... Turntable, 4... Crucible, 5... Shutter, 6...
·slit. Patent applicant Fujitsu Limited Patent attorney Akira Aoki Patent attorney Kazuyuki Nishidate 1) Yukio Patent attorney Akira Yamaguchi Figure 1

Claims (1)

[Claims] ■ The resist film is exposed to a laser beam and developed to form a master disc with recesses corresponding to the ID groups of the optical disc, and a thin metal film that is easily peeled is first vacuum-deposited on the resist of this master disc. , by depositing thick metal films on top of this thin film and increasing these metal films from the resist.
A stamper is formed with a protrusion corresponding to the guide group of the optical disc. A method for manufacturing a pre-group stamper for an optical disc, characterized in that the metal thick film is formed by a vacuum evaporation method.