Electrostatic chuck with anti-reflective coating, measuring method and use of said chuck

摘要

The embodiments disclosed herein relate to an electrostatic chuck, or an optically structured element or an optical mask that comprise a metal film as well as a transparent cover applied on a substrate. At least two anti-reflective films are inserted between the metal film and the cover that reduce the reflectance of the metal film, as viewed from the surface, to almost zero. As a result, a direct interferometer measurement of the surface structure of the transparent cover is possible. Methods of measurement and of use are also disclosed.