PHOTOMASK, PRODUCTION AND INSPECTION THEREOF AND DRY-ETCHING METHOD FOR TRANSPARENT SUBSTRATE

摘要

PURPOSE:To improve a transmittance and an etching accuracy of a photomask concerning a production method and an inspection method related to a phase shift mask. CONSTITUTION:The photomask is composed of a dry-etching surface 3 in which at least the surface of a light transmission part of a transparent substrate 1 is made porous. The surface of the transparent substrate 1 is subjected to a dry-etching in a plasma to form the porous dry-etching surface 3. The both surfaces of a main pattern 5 and a shifter pattern 6 of the phase shift mask 4 are formed to the porous dry-etching surfaces 3. An optical fiber 9 is provided at the back face of the transparent substrate 1 and light quantity of the transmitted light 11 which is made incident on the optical fiber 9 after transmitting the transparent substrate 1 from a light source 10 is measured and the dry- etching is stopped when an etching amount of the transparent substrate 1 attains the prescribed depth. By using light 13 having <=300nm wavelength, transmittance is measured and thereby the depth uniformity of the surface of the pattern 6 is inspected.