PHOTOMASK BLANK AND PHOTOMASK

摘要

PURPOSE:To prevent the electrostatic breakdown of a light shieldable metallic pattern and to improve durability by laminating a transparent conductive film, transparent insulating film and light shieldable metallic film on a transparent base plate. CONSTITUTION:An SnxSbyOz film 12 (about 150Angstrom film thickness) is laminated by sputtering method as a transparent conductive film on the main surface of soda glass 11 which is a transparent base plate and a transparent insulating film 13 (about 100Angstrom film thickness) consisting of SiO2 as a blank material is laminated on the film 12 by the same method. A chromium film 14 (about 700Angstrom thickness) adjusted in optical density to a reference value (for example, 3.0) is laminated by the above-described sputtering method as a light shieldable metallic film on the film 13 by which a photomask blank 15 is produced. Photoresist 16 made on the blank 15 and the pattern of the resist 16 is formed on the mask. The film 14 in the pattern part is left and a chromium pattern 20 is obtd.