Patent ID: 7648671

Claim:
A method of making a master for manufacturing an optical disc comprising: an exposing step of applying a laser beam for recording, modulated by an information signal corresponding to an information signal of an information concave and convex pattern to be formed on said optical disc, to an inorganic resist layer of said master formed on a substrate to form an exposed pattern corresponding to said information concave and convex pattern of said optical disc, and after the preceding step a developing step of performing development processing on said inorganic resist layer to form a concave and convex pattern corresponding to said information concave and convex pattern of said inorganic resist layer, wherein in said exposing step, a laser beam for estimation is applied to a predetermined area on said inorganic resist layer to estimate information signal characteristics of said exposed pattern of said inorganic resist layer using reflected light of the laser beam for estimation, and power of said laser beam for recording is controlled based on the estimated result, wherein said laser beam for estimation is applied to an unexposed area and an exposed area corresponding to where said laser beam for recording formed a portion of the pattern corresponding to said information concave and convex pattern of said optical disc, and the information signal characteristics of said exposed pattern of said inorganic resist layer are estimated to derive the estimated result using a ratio between reflected light amount from said unexposed area and reflected light amount from said exposed area, with said laser beam for estimation.