JPS6284448A - Stamper for optical memory element substrate - Google Patents

Abstract

PURPOSE:To increase the surface hardness of a stamper and to improve the durability thereof by forming a nitride layer on a base material of the stamper for an optical memory element substrate and forming information bits, guide tracks, etc. on the nitride layer. CONSTITUTION:An AlN layer 2 is formed by a sputtering method or the like on a metallic sheet 1 and a photosensitive layer 3 is formed thereon. An information signal or guide tracks are recorded by laser light, etc. on the photosensitive layer 3 and thereafter said layer is developed. The AlN layer 2 is etched by the depth necessary for the guide tracks with the photosensitive layer 3 as a mask. The photosensitive layer 3 on the AlN layer 2 is removed by oxygen plasma, etc. and the stamper having the surface consisting of the AlN layer 2 is obtd. Since the stamper surface is the nitride layer 2 having extremely high Mohs' hardness (the Mohs' hardness is 7 in the case of AlN), the wear resistance is remarkably improved.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an improvement in a stamper for an optical memory element substrate used for manufacturing an optical memory element that records, reproduces, erases, etc. information using optical means such as a laser beam. It is something.

(Prior Art) In recent years, as the demand for optical memory devices capable of large capacity, high density, and high-speed access has increased, research and development of optical memory devices using synthetic resins such as acrylic resin as substrates has been actively conducted. There is.

Conventionally, the production of such synthetic resin substrates requires a stamper, and this type of stamper has been produced in many cases by two methods.

The first method is to form a photosensitive layer on a glass plate, record information signals or guide tracks on the photosensitive layer with a laser beam, etc., coat it with a conductive film, and then manufacture a stamper by electroforming. This is the way to do it.

In the second method, a photosensitive layer is formed on a metal plate, information signals or guide tracks are recorded on the photosensitive layer using a laser beam, etc., and then the metal plate is etched using the photosensitive layer as a mask. This method uses a board as a stamper.

(Problems to be Solved by the Invention) Conventionally, Ni has been used as the metal used in the second method, but its surface hardness as a stamper is not sufficient, and for this reason, it cannot be used repeatedly. There was a problem in that the surface shape deteriorated over time. Such a phenomenon is noticeable when the synthetic resin used for the substrate has a high viscosity or when used in a state with poor fluidity, and has been a cause of shortening the life of the stamper.

(Means for Solving the Problems) The stamper for an optical memory element substrate of the present invention has a nitride layer formed on a base material, and information bits, guide tracks, etc. are formed on this nitride layer.

(Function) Since the surface of the stamper on which information bits, guide tracks, etc. are formed is a nitride layer, the stamper has high surface hardness and excellent durability.

(Example) Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

In FIG. 4, the stamper for an optical memory element substrate according to the present invention is, for example, a glass plate or Aj! A nitride layer 2 is formed on a base material l made of a metal plate such as , Ni, etc., and information bits, guide tracks, etc. are formed on this nitride layer 2.

As the nitride layer 2, for example, A I N, SiN
.

Examples include TiN, TaN, and BN.

Next, an embodiment of the method for manufacturing the stamper for an optical memory element substrate as described above will be described with reference to FIGS. 1 to 4.

Process fil...Fig. 1 A/
N layer 2 is formed by sputtering method etc., and the A7! N layer 2
A photosensitive layer 3 is formed on -1- by a spinner method, a spray method, a dip method, or the like.

Step (2)...FIG. 2 An information signal or a guide track is recorded on the photosensitive layer 3 with a laser beam or the like, and then developed. FIG. 2 shows the state after development.

Step (3)...Figure 3 Next, using CF or CHF 3 Blazoon gas as a mask, A7! Etch the N layer 2 to the depth required for the guide track. FIG. 3 shows the state after etching is completed.

Step (4)...FIG. 4 The photosensitive layer 3 of the AIN layer 2-1- is removed by oxygen plasma or the like to obtain a stamper whose surface is the /ltN layer 2.

According to the present invention, since the surface of the stamper is a nitride layer 2 with extremely hard Mohs hardness (Mohs hardness is 7 in the case of AlIN), wear resistance is greatly improved.

Note that recording of information signals and guide tracks may be performed by a contact exposure method using ultraviolet light instead of laser light.

(Effects of the Invention) According to the present invention, not only the life of the stamper is significantly extended, but also a material other than Ni can be used for the metal of the stamper.

[Brief explanation of drawings]

FIGS. 1 to 4 are process diagrams showing one embodiment of a method for manufacturing a stamper for an optical memory element substrate according to the present invention. 1... Base material 2... Nitride layer 3... Photosensitive layer Fig. 7

Claims (1)

[Claims] 1) A stamper for an optical memory element substrate, characterized in that a nitride layer is formed on a base material, and information bits, guide tracks, etc. are formed on this nitride layer.