Ultraviolet light detector for laser monitoring in photolithography has coating which converts incident UV radiation into light of longer wavelength

摘要

Light detector includes light-sensitive element (102) and frequency converting coating (104) that absorbs incident ultraviolet light and re-emits longer wavelength light in direction of the light sensitive element whose life is increased because the rate of growth of the dark current background noise in response to the total accumulated radiation exposure is reduced by a factor of ten or more. The coating converts incident radiation having a wavelength lass than 240 nm into light having wavelength greater than 240 nm. The light may be from an ArF excimer laser, an F2 laser or a YAG laser source. An Independent claim is given for a laser system with a light detector.