| 摘要 |
PURPOSE:To prevent damage of a light shading pattern without impairing any function of a photomask and to extend its life by forming a protective film of SiO2 on the whole surface of a quartz glass substrate on which the light shading pattern is formed. CONSTITUTION:A Cr pattern 2 having a 2-layer structure of Cr and Cr oxide is formed on a quartz glass substrate 1. On the whole surface of the substrate 1 a polysilicone film 3 is formed by the chemical gas phase growth method to 200-1,000nm thickness, then, placed in a furnace at about 1,100 deg.C, and heat oxidized to convert the polysilicone film 3 into an SiO2 film 4, thus obtaining a protective film. |
