Radiation system and lithographic apparatus

摘要

A radiation system for generating a beam of radiation is disclosed. The radiation system includes a pulsed EUV source (2) for generating EUV radiation, and a spectral filter (5) mounted in front of the EUV source for selectively passing a spectral range of a beam of EUV radiation from the EUV source. The spectral filter is mounted on a movable mount (6) configured to be moved in synchronicity with the pulsed EUV source to prevent debris traveling from the EUV source from impacting the spectral filter. Accordingly, the spectral filter is kept substantially free from contamination by the debris.