Patent ID: 6874262

Claim:
A method for manufacturing a master substrate for producing a grooved molded substrate comprising: (1) preparing a ceramic substrate on which a photoresist is coated; (2) exposing the photoresist along a line with exposing light having an effective diameter, the resultant photoresist having a linear part that is exposed to the exposing light and a linear part that is not exposed to the exposing light, the exposed part corresponding to a land of the grooved molded substrate to be produced, the unexposed part corresponding to a groove of the grooved molded substrate to be produced, the width of the exposed part being determined by the effective diameter of the exposing light and wider than the width of the unexposed part, the width of the unexposed part being determined by the width of the exposed part and a distance by which the exposing light is moved to expose the ceramic substrate along an adjacent line so that the width of the unexposed part is not greater than 0.06 μm; (3) developing the photoresist to form a resist pattern: (4) etching a part of the ceramic substrate using the resist pattern as a mask; and (5) removing the photoresist to yield the master substrate.