Development Of Wide Ion Beam Profile Measurement Method For A Period-By-Period Extreme Ultraviolet Multilayer Milling System

To develop an ion milling system for multilayer mirrors in the extreme ultraviolet (EUV) wavelength region, the current density profile of a phi 100-mm-ion beam has been measured by plural methods. The profile has been measured indirectly via milling thickness by an optical surface profiler (WYKO TOPO-2D) and an X-ray diffractometer. Direct current detection by a commercial Faraday cup and a newly developed array electrode sensor was also performed. These methods were compared and evaluated in terms of their experimental results. It was demonstrated that our array electrode sensor is useful for observing a wide ion beam profile with reasonable accuracy. (C) 2010 The Japan Society of Applied Physics