PHOTOMASK AND ITS PRODUCTION

摘要

PURPOSE:To prevent an increase of the thickness of a thin film antireflection layer by providing a thin film light shielding layer consisting of a high refractive index material and the thin film antireflection layer which is directly stuck onto the surface of the light shielding layer and consists essentially of tantalum oxide or tantalum nitride or the mixture composed thereof to the titled photomask. CONSTITUTION:A photomask blank 11 consists of a substrate 12 consisting of synthetic quartz glass, the thin film light shielding layer 13 which is stuck onto the surface of the substrate 12 and consists of molybdenum silicide and the thin film antireflection layer 14 which is stuck onto the surface of the thin film light shielding layer 13 and consists essentially of the tantalum oxide and tantalum nitride. The molybdenum silicide is the high refractive index material and the thin film antireflection layer 14 essentially consisting of the tantalum oxide and tantalum nitride has high resistance to acids and alkalis and high refractive index. The photomask which has the excellent optical characteristics, dry etching property and resistance to acids and alkalis and has consequently the high accuracy of pattern transfer at the time of photolithography is thus obtd. while the undesirable increase of the thickness of the thin film antireflection layer 14 is suppressed.