Photomask and manufacture therefor

Abstract

Abstract PURPOSE:To greatly lessen the extent of degradation of the intensity of exposure light at lower edge parts and to eliminate the formation of an unnecessary pattern by making thinner the film thickness of a sifter at the edge part of the sifter on a light translucent part as the sifter goes toward the edge. CONSTITUTION:In a photomask 31, the film thickness on the part a of the light translucent part between light shielding parts 15 of the sifter 33 is set at (t) and this (t) is made to be lambda/2(n-1), where the most effective result as the sifter for a phase shift method is obtained; lambda is a wavelength of light exposure, and (n) is the reflective index of the structural material of the sifter at a wavelength lambda. The structural materials of the sifter are inorganic materials of silicone dioxide, etc., and polymers, etc. Besides the film thickness at the edge part 33a is made thinner gradually as the film goes toward the edge part, and the part (b) is about 3 t/4, and the part c is about t/2 and the part d is about t/4. In this photomask 31, at each of the sifter boundaries such as the part (a) and the part (b), the reduction of the light intensity caused by the phase shift of the exposure light beams transmitting through both sides of the boundaries occurs, but since the film thickness is decreased gradually, the reduction of the light intensity as much as the generation of pseudo unexposured part occurs is not generated and the desired pattern without an unnecessary pattern is obtained.

Inventors

• 👤 Hideyuki Jinbo
• 👤 神保　秀之
• 👤 Yoshiyuki Kawazu
• 👤 佳幸 河津
• 👤 Yoshio Yamashita
• 👤 山下　吉雄

Bibliographic Details