Arrangement and method for protecting an optical component, particularly in an EUV source

摘要

An arrangement and a method for protecting an optical component (27) in or on a process chamber, through which component optical radiation passes or by which optical component optical radiation is produced or reflected. The arrangement comprises an optical plate (28) that is arranged in front of the optical component and an orificed mask (29) that is arranged in front of the optical plate and that has an orifice through which a region of the surface of the optical plate is exposed on a preset axis of the beam of optical radiation. Remaining regions of the surface of the optical plate are covered, on the orificed-mask side, by the orificed mask and/or by other screening elements for protecting against fouling. The optical plate is so moved in translation and/or rotation that different regions of the surface are exposed in succession through the orifice of the orificed mask. The present arrangement and the associated method produce a lengthening of the life of the optical component and hence of the interval between two maintenance operations.