JPS6079351A - Manufacture of stamper - Google Patents

Abstract

PURPOSE:To maintain the planenss of a glass substrate and to manufacture a stamper with high transfer accuracy at a low cost while almost preventing the sticking of dust by applying a photoresist to a metallic thin film formed on the glass substrate, making the surface of the photoresist uneven, depositing a metal, and removing the photoresist. CONSTITUTION:A metallic thin film 8 of nickel or the like is formed on a glass substrate 1 by sputtering, vacuum deposition or other method, and a photoresist 2 is applied to the film 8 to a larger thickness than the depth of pits with a spinner or the like. The photoresist 2 is exposed to laser light modulated with an information signal, and it is developed to form projections corresponding to the information signal on the film 8. A metallic thin film 9 having a thickness equal to the necessary depth of pits is formed on the uneven surface by sputtering, vacuum deposition or other method. The film 9 is made of the same metal as the film 8. The photoresist 2 is then removed. Only the film 9 deposited in the recesses remains on the film 8, and a stamper is manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a method for manufacturing a stamper used for manufacturing information recording media. More specifically, the present invention relates to a 2P stand, a, for producing a pregrooved substrate for an optical disc.

Prior Art Conventional optical disk substrates are manufactured by the procedure shown in FIGS. 1 to 6. First, a photoresist film 2 (40 to 130 nm)' is coated on a glass substrate 1, exposed to laser light and developed to form pits and pregrooves 2'.
(width 0.5 to 1.0 μm) (Fig. 1). Next, silver or nickel is deposited on this by sputtering or vacuum evaporation to form a conductive film 3 (Figure 2).
. Using this conductive film 3 as a cathode, a nickel plate 4 is formed by electroforming (FIG. 3). A stamper (master) is obtained by removing the glass substrate 2 from the electroforming plate 4 together with the conductive film 3 (FIG. 4).

An ultraviolet curing resin 6 is placed between the thus produced stamper and the acrylic substrate 50, and the shapes of the pits and pregrooves are transferred to the ultraviolet curing resin 6, and the ultraviolet rays 7 are irradiated from the side of the acrylic substrate 5 to cure it. Figure 5). This is peeled off from the stamper to form a substrate (FIG. 6). This method of manufacturing a substrate using an ultraviolet curing resin without applying high temperature and high pressure to a stamper as in injection molding is called a 2P method. In such conventional methods, flatness deteriorates during the process of peeling off the stamper from the glass substrate, and since there are many stamper manufacturing steps, dust may adhere during the process, resulting in poor transfer accuracy (and high production costs). was there.

Purpose The present invention was made in view of the above-mentioned problems, and its purpose is to maintain the flatness of the glass substrate, reduce the number of manufacturing steps, reduce the chance of dust adhesion, improve transfer accuracy, and reduce manufacturing costs. An object of the present invention is to provide a method for manufacturing an inexpensive stamper.

Structure The method for manufacturing a stamper according to the present invention involves forming a metal thin film on a glass substrate, applying a photoresist on the metal thin film, exposing and developing the photoresist to form irregularities, and then attaching metal. and then removing the photoresist. According to another method of the present invention, instead of forming the unevenness as described above and then attaching the metal, the metal thin film is etched using the photoresist on the metal thin film as a mask, and then the photoresist is removed and the stamper is etched. can be created. Here, "unevenness" means pits or pregrooves that correspond to information signals.

An embodiment of the stamper manufacturing method of the present invention will be described in detail below with reference to the accompanying drawings.

As shown in FIG. 7, a thin metal film 8 of nickel or the like is formed on the glass substrate 1 by sputtering or vacuum vapor deposition, and then a photoresist film as thick as the υ pit depth is deposited on this using a spinner or the like. form 2. Next, the metal thin film is irradiated with a laser modulated by the information signal, exposed, and then developed to form irregularities (pits 2') corresponding to the information signals on the metal thin film (FIG. 8).

Next, as shown in FIG. 9, the same metal used to form the metal thin film 8 is deposited on the unevenness (pits, groups) by sputtering or vacuum evaporation to form a metal thin film with a film thickness equal to the required pit depth. form 9. Then the 9th
When the photoresist shown at 2 in the figure is removed, only the metal thin film 9 attached in the groove is left as shown in FIG.
The stamper of the present invention is produced by remaining on top.

In another embodiment of the present invention, a metal thin film 8 is formed on a glass substrate 1 in the same manner as described above except that the thickness of the metal thin film is made equal to the pit depth, and then a photoresist 2 is formed on the glass substrate 1.
(Figure 8). Next, using the photoresist 2 on the metal thin film 8 as a mask, etching is performed to form pits 2' as shown in FIG. Next, when the photoresist 2 is removed, a metal thin film 8 remains on the glass substrate 1, and a stamper as shown in FIG. 12 is manufactured.

It should be noted that the above-mentioned embodiments are given for illustrating the present invention, and it goes without saying that various modifications can be made within the scope of the gist of the present invention.

effect According to the method of the present invention, the following effects can be obtained.

a) Since a glass substrate with good flatness is used as it is as a stamper substrate, the flatness is much better than that of conventional stampers.

b) Since the number of steps is small, there is less opportunity for dust to adhere (
The transfer accuracy is good and the production cost is low.

C) Since there is no plating process, there is no environmental pollution caused by processing of plating solution.

d) When using an ultraviolet curable resin, unlike injection molding, heat and pressure are hardly applied, so the glass substrate of the present invention can be used satisfactorily.

[Brief explanation of drawings]

1 to 6 are partial sectional views illustrating the manufacturing process of a conventional stamper, and FIGS. 7 to 12 are partial sectional views illustrating the manufacturing process of the stamper of the present invention. 1...Glass substrate, 2...Photoresist, 2'.
... pit or pregroove, 3... conductive film, 4.
...Nickel electroformed plate, 5...Acrylic plate, 6...Ultraviolet curing resin, 7...Ultraviolet light, 8,9...Metal thin film. Patent applicant Rico Co., Ltd. - Figure 7

Claims (1)

[Claims] 1) A thin metal film is formed on a glass substrate, a photoresist is applied on the thin metal film, the photoresist is exposed and developed to form irregularities, and then metal is attached. A method for manufacturing a stamp pano, which is characterized in that the photoresist is then removed. 2) Form a metal thin film on a glass substrate, apply 7 photoresist on this metal thin film, expose and develop this photoresist to form unevenness, and then use the photoresist on the metal thin film as a mask. A method for manufacturing a stamper, comprising etching the metal thin film and then removing the photoresist.