An extreme ultra-violet lithographic apparatus for imaging a pattern onto a substrate includes a radiation system constructed and arranged to provide a beam of an extreme ultra-violet radiation, and an absorber arranged in the beam and constructed and arranged to absorb at least a portion of the radiation...http://www.google.de/patents/US7816658?utm_source=gb-gplus-sharePatent US7816658 - Extreme ultra-violet lithographic apparatus and device manufacturing method
