Photomaskenrohling, Photomaske und deren Herstellungsverfahren

摘要

A light-shielding film (12) for exposure light is formed on one principal plane of a transparent substrate (11) made of quartz or the like that serves as a photomask substrate. The light-shielding film (12) can serve not only as the so-called "light-shielding film" but also as an anti-reflection film. In addition, the light-shielding film has a total thickness of 100 nm or less, 70 % or more of which is accounted for by the thickness of a chromium compound that has an optical density (OD) per unit thickness of 0.025 nm -1 for light having a wavelength of 450 nm. In the case where the photomask blank is used for fabricating a mask designed for ArF exposure, the thickness and composition of the light-shielding film (12) are selected in such a manner that the OD of the light-shielding film (12) is 1.2 to 2.3 for 193 or 248 nm wavelength light.