Patent ID: 8242471
Filing Date: 2012-08-14
Classification: G03F,G21K,H05G

Abstract:
1. A radiation source comprising: a radiation emitter configured to emit radiation; a collector constructed and arranged to collect the radiation, the collector comprising a plurality of reflective shells provided within one another; and a contamination trap constructed and arranged to trap contamination emitted by the radiation emitter, the contamination trap comprising a plurality of foils that extend substantially radially, a first magnet ring configured to lie outside of an outer conical trajectory of radiation that is collected by the collector, and a second magnet ring configured to lie within the trajectory of radiation that is collected by the collector and substantially aligned with a reflective shell of the collector, wherein the magnet rings are configured to provide a magnetic field that includes a component that is parallel to the foils, and wherein the foils are provided between the reflective shells of the collector.