METHOD FOR MANUFACTURING MASTER DISK FOR OPTICAL DISK AND APPARATUS FOR THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a method for manufacturing a master disk for optical disks which detects the end point of etching with good accuracy and an apparatus for the same in a method for manufacturing a stamper for optical disks by etching a substrate. SOLUTION: The substrate is provided with a monitor zone consisting of continuous grooves at a region exclusive of its data region of the substrate and a laser beam is cast to this monitor zone during etching or during the course of the etching. The progression state of the etching is known by detecting the intensity of the diffracted light and the etching is ended at a suitable point.