Optical element, lithographic apparatus including such an optical element, device manufacturing method, and device manufactured thereby

• Main Authors: JOHANNES HUBERTUS JOSEPHINA MOORS, MAARTEN MARINUS JOHANNES WILHELMUS VAN HERPEN, ANDREY MIKHAILOVICH YAKUNIN, WOUTER ANTHON SOER, VADIM YEVGENYEVICH BANINE
• Format: Patent
• Language: Dutch
• Published: 31.08.2009
• Subjects: APPARATUS SPECIALLY ADAPTED THEREFOR; CINEMATOGRAPHY; ELECTROGRAPHY; GAMMA RAY OR X-RAY MICROSCOPES; HOLOGRAPHY; IRRADIATION DEVICES; MATERIALS THEREFOR; NUCLEAR ENGINEERING; NUCLEAR PHYSICS; ORIGINALS THEREFOR; PHOTOGRAPHY; PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES,e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTORDEVICES; PHYSICS; TECHNIQUES FOR HANDLING PARTICLES OR IONISING RADIATION NOTOTHERWISE PROVIDED FOR

An optical element includes a first layer that includes a first material, and is configured to be substantially reflective for radiation of a first wavelength and substantially transparent for radiation of a second wavelength. The optical element includes a second layer that includes a second material, and is configured to be substantially absorptive or transparent for the radiation of the second wavelength. The optical element includes a third layer that includes a third material between the first layer and the second layer, and is substantially transparent for the radiation of the second wavelength and configured to reduce reflection of the radiation of the second wavelength from a top surface of the second layer facing the first layer. The first layer is located upstream in the optical path of incoming radiation with respect to the second layer in order to improve spectral purity of the radiation of the first wavelength.