SUBSTRATE FOR PHOTOMASK AND PHOTOMASK BLANK

摘要

PURPOSE: A substrate for photomask and a photomask blank is provided to reduce photomask manufacture costs by re-grinding a transparent substrate and reusing it. CONSTITUTION: In a substrate for photomask and a photomask blank, a photomask having a metal layer pattern therein is provided. A metal layer pattern is removed from the photomask. The photomask is re-ground and the transparent substrate for photomask is formed. The area of the transparent substrate is less than 5000cm^2. The difference between the width and height of the transparent substrate is less than 200mm. The transparent substrate is re-ground to have thickness over 0.2mm.