| 摘要 |
PURPOSE:To form a light shielding metal thin film pattern for a photomask of high accuracy by using a two-layer structure film composed of a water soluble resin film and a photosensitive corrosion resistant film as a film for forming the pattern. CONSTITUTION:On substrate 1 resin film 7 such as polyvinyl alcohol film and photosensitive corrosion resistant film 2 are formed by coating, and a film 2 portion corresponding to a light shielding mask pattern forming portion is removed by a photographic development method. The exposed film 7 portion is also removed by dissolution while forming undercut portion 8. Next a photomask material such as Cr is attached to the whole surface of substrate 1 thus treated, forming metal thin films 4, 4'. At this time, film 4 is regulated by the pattern edge of film 2, and a fine gap is left between the periphery of film 4 and film 7. Film 7 is then removed by dissolution together with upper film 2 and thin film 4 to form light shielding portion 5 of film 4' for a photomask. |
