SPECTRAL PURITY FILTER, LITHOGRAPHIC APPARATUS, AND METHOD FOR MANUFACTURING A SPECTRAL PURITY FILTER

摘要

A transmissive spectral purity filter configured to transmit extreme ultraviolet radiation includes a filter part having a plurality of apertures to transmit extreme ultraviolet radiation and to suppress transmission of a second type of radiation. The apertures may be manufactured in semiconductor material such as silicon by an anisotropic etching process. The semiconductor material is provided with a hydrogen-resistant layer, such as silicon nitride Si3N4, silicon dioxide SiO2, or silicon carbide SiC.