| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing an optical disk substrate and an optical master disk having a shape with which a land prepit(LPP) and neighboring grooves thereof do not affect groove recording quality when pits and grooves having different depths are formed in the same master disk by using plasma etching and an ashing process. SOLUTION: When the LPP is formed between shallow grooves or between shallow pits, the LPP is formed on a land existing between shallow grooves or between shallow pits and at a position displaced from the central line of the land in the radius direction by a prescribed quantity. Further the laser power for forming shallow grooves or shallow pits near the LPP is made to be smaller than usual laser power. |
