Patent ID: 7709161

Claim:
A photomask blank serving as a base member for producing a halftone-type phase shift mask in which a light-transmissive substrate is formed thereon with a light-semitransmissive phase shift pattern having a desired opening, said photomask blank comprising: a light-semitransmissive phase shift film formed on said light-transmissive substrate; a chromium film formed on said light-semitransmissive phase shift film as an opaque film; and an etching mask film formed on said chromium film and made of an inorganic-based material having a resistance against dry etching of said chromium film, wherein said chromium film is made of a material selected from the group consisting of CrO, CrN CrC, CrCO, CrCN, CrON, and CrCON, wherein said etching mask film is made of a material selected from the group consisting of MoSiO, MoSiN, MoSiON, and SiON.