HIGHLY RELIABLE MODULAR NARROW BAND PRODUCTION QUALITY KrF EXCIMER LASER

摘要

PROBLEM TO BE SOLVED: To attain a stabilized wavelength ensuring long term production operation and highly reliable product quality by including a more accurate wave meter and a laser computer controller of novel pulse energy control algorithm. SOLUTION: A preionization unit includes, as an integrated component, a brushing element incorporated with an antitracking groove. A part of acoustic energy is reflected and absorbed by arranging acoustic baffles on the opposite sides of a laser chamber and dropped into a lower region of the laser chamber separated from an electrode. Gas flow from a blower 10 is forced to flow between electrodes 6A, 6B by means of an anode supporting bar 44. A wave meter blocks an output beam from the laser chamber by means of a partial reflector which transmits about 95.5% of beam energy and reflects about 4.5% thereof. Detector output is fed to a computer controller using a specified algorithm for regulating the laser charge voltage.