Increased-contrast film for high-transmittance attenuated phase-shaft masks

摘要

An increased-contrast film for high-transmittance attenuated phase-shift masks (PSM's) is disclosed. A high-transmittance attenuated PSM includes a clear substrate, a shifter film selectively covering the clear substrate, and an increased-contrast film covering the shifter film to aid inspection of the PSM. The increased-contrast film may be removable, and may be photoresist. The increased-contrast film is preferably non-reactive to light used during the inspection of the PSM.