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Title
VERFAHREN UND VORRICHTUNG ZUR UNTERDRUECKUNG VON LICHTABSORPTION, LICHTSTREUUNG UND KONTAMINATION BEI WELLENLAENGEN UNTERHALB VON 200NM
Date Issued
2004
Author(s)
Duparre, A.
Gliech, S.
Notni, G.
Steinert, J.
Patent No
2001-10147089
Abstract
WO2003029789 A UPAB: 20030516 NOVELTY - Method involves partial evacuation of the gas molecules in the beam path, so that a sub-atmospheric pressure is generated and then simultaneously or subsequently introducing a flushing gas into the beam path. The sub-atmospheric pressure is maintained even after introduction of the flushing gas. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is made for a device for reducing light absorption and dispersion caused by gas molecules in optical applications using light of wavelength less than 200 nm. USE - Light of wavelength less than 200 nm is used for measuring scattering and transmission and in ellipsometry using light of 157 and 193 nm wavelength. It also used in VUV microscopy, lithography and imaging systems. ADVANTAGE - The inventive method reduces light absorption to at most 50 %, while preventing contamination of optical components that would be caused if a vacuum method was used without a flushing gas.
Language
de
Patenprio
DE 2001-10147089 A: 20010925