Photomask blanks

摘要

Transmissive embedded phase shifter-photomask blanks are disclosed which comprise an optically inhomogeneous attenuating film which has a transmission of at least 0.001 and consists essentially of a combination of a metallic component and a dielectric component. One surface of the film has a higher content of metallic component than the other surface and the profile of change in extinction coefficient is gradual through the film thickness. The profile of change in extinction coefficient and the film thickness are selected to provide a phase shift of about 180 DEG (or an odd multiple thereof) at a selected wavelength.