PHOTOMASK BLANK, PHOTOMASK AND METHOD FOR PRODUCING THESE

摘要

PROBLEM TO BE SOLVED: To obtain a photomask blank capable of easily controlling etching rate and giving a perpendicular section shape, to obtain a photomask blank and a photomask uniform in film quality and having high quality and to make the photomask adaptable to further miniaturization and integration of a semiconductor integrated circuit. SOLUTION: In the photomask blank having at least one chromium-base light shielding film and at least one chromium-base antireflection film on a light transmissive substrate, each of the light shielding film and the antireflective film is formed from a chromium-base film containing oxygen, nitrogen and carbon and the carbon content is stepwise or continuously lowered from the surface side toward the light transmissive substrate.