To locate/size contaminants at the surface of a dielectric or semiconductor material, a P-polarized beam of light from a monochromatic solid-state source is disposed specifically at Brewster's angle and focused to form an illuminated quasi-elliptical spot on the surface that produces effectively no reflected...http://www.google.de/patents/US7002675?utm_source=gb-gplus-sharePatent US7002675 - Method and apparatus for locating/sizing contaminants on a polished planar surface of a dielectric or semiconductor material
