Characteristics of deep UV optics at 193nm & 157nm

The increasing use of Argon Fluoride (ArF) 193nm excimer lasers in microlithography, surgical procedures and other applications have created the requirement for an increasingly larger number of specialized optical components and thin film coatings. At 193nn these include coated components that can withstand long duration exposure to ultraviolet (UV) radiation without significant change in performance. Similar coatings and components for Fluorine (F-2) lasers operating at 157nm are under development. At these deep UV (DUV) wavelengths, potential coating materials as well as substrates are very limited due to absorption and impurities. Characteristics of various types of thin film coatings including reflective, anti-reflective, beam-splitting, beam attenuating and optical bandpass filters, at both 193nm and 157nm, are measured using a specially designed vacuum spectrophotometer system. Results of these measurements as well as plans for further coating development are presented.