The invention relates to an apparatus for measuring thickness and deviations from the thickness of thin conductive coatings on various substrates, e.g., metal coating films in semiconductor wafer or hard drive disks. The thickness films may be as small as fractions of microns. The apparatus consists...http://www.google.de/patents/US6593738?utm_source=gb-gplus-sharePatent US6593738 - Method and apparatus for measuring thickness of conductive films with the use of inductive and capacitive sensors
