Methods and apparatus for enabling both isolated and dense patterns to be accurately patterned onto a wafer are disclosed. According to one aspect of the present invention, an illumination system that is suitable for use as a part of a projection tool includes an illumination source and an illuminator...http://www.google.es/patents/US6842223?utm_source=gb-gplus-sharePatente US6842223 - Enhanced illuminator for use in photolithographic systems
Enhanced illuminator for use in photolithographic systems
