Skip to Content
Find More Like This
Return to Search

Method for reducing carbon contamination of multilayer mirrors

United States Patent Application

View the Complete Application at the US Patent & Trademark Office
Sandia National Laboratories - Visit the Intellectual Property Management and Licensing Website
A method for reducing carbon contamination of surfaces and particularly the surfaces of multilayer mirrors used for extreme ultraviolet (EUV) lithography by manipulating the surface electric phase field to reduce photoemission. Manipulation of the surface electric phase field can be by depositing a film, such as Si, or other low absorber of EUV radiation, to form a capping layer whose thickness is such that the near-surface electric field is a minimum. For extreme ultraviolet applications, where a multilayer Mo/Si mirror is used as a reflective optic, a capping layer of Si in the range of about 2-4 nm, and preferably 3 nm, is used.
Malinowski, Michael E. (Livermore, CA)
10/ 198,307
July 17, 2002
[0002] This invention was made with Government support under contract no. DE-AC04-94AL85000 awarded by the U.S. Department of Energy to Sandia Corporation. The Government has certain rights in the invention.