US 4,655,876 AGranted

Method for fabricating a master recording disc

AssigneeVictor Company of Japan, Ltd.

InventorsNoboru Kawai, Toshiro Abe, Kei Murata

Life of this patent

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Abstract

In a method of fabricating a master recording disc, a photoresist layer is formed on a glass substrate to form a master blank, which is revolved and exposed to an intensity-modulated laser beam so that a series of optically excited regions is formed in track turns in the photoresist layer. The optically excited regions are removed, forming a series of pits in the photoresist layer. An etchant gas is sputtered onto the master blank until the pits in the photoresist layer extend through the boundary surface of the photoresist layer and the glass substrate to a desired depth and pits having side walls tapered in a direction away from the boundary surface are formed in the substrate. The photoresist layer which remains on the glass substrate is finally removed.

Claims6

Dependent claims

A method for fabricating a master recording disc comprising:

(a) forming a photoresist layer on a glass substrate to form a master blank;
(b) revolving said master blank;
(c) directing a laser beam onto the surface of the revolving photoresist layer, said laser beam being modulated in intensity with a signal to be reproduced so that a series of optically excited regions is formed in track turns in said photoresist layer;
(d) removing said optically excited regions to form a series of pits in said photoresist layer;
(e) sputtering said master blank with an etchant gas until the pits in the photoresist layer extend through and beyond the boundary surface of the photoresist layer and the glass substrate to a desired depth from said boundary surface and pits having side walls tapered in a direction away from said boundary surface are formed in said substrate;
and
(f) removing said photoresist layer which remains on said glass substrate.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 06/753,755Filed 11 Jul 1985
Priority: JP 59-14527214 Jul 1984
Granted: 7 Apr 1987
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

G11B 23/0085
Mediums or carriers characterised by the selection of the material: intermediate mediums using a photosensitive material, e.g. photo-resist
G11B 7/261
Apparatus or processes specially adapted for the manufacture of record carriers: preparing a master, e.g. exposing photoresist, electroforming
Y10S 430/146
Radiation imagery chemistry: process, composition, or product thereof: laser beam
G11B
Information storage based on relative movement between record carrier and transducer