Patent ID: 7691546

Claim:
A photomask blank, from which a photomask comprising a transparent substrate and a mask pattern formed thereon including transparent regions and effectively opaque regions to exposure light can be produced, comprising: a transparent substrate; and a light-shielding film and an antireflective film in the form of a binary mask blank, wherein the light-shielding film and the antireflective film are formed on the transparent substrate with or without another film (A) intervening therebetween, the light-shielding film comprises one or more layers, at least one layer (B) of the layers containing silicon and a transition metal as main components, the silicon and the transition metal are present at a silicon/metal molar ratio of 4/1 to 15/1, and combination of the light-shielding film and the antireflective film has an optical density of at least 2.5.