Patent ID: 6633170
Filing Date: 2003-10-14
Classification: G01N,H01L

Abstract:
A method for identifying high metal surface content substrate comprising:providing a semiconductor substrate; providing a source of microwave radiation; providing a first and second microwave energy measurement apparatus; exposing said semiconductor substrate to microwave radiation provided by the source of microwave radiation; capturing, by said first microwave energy measurement apparatus, microwave energy reflected by said semiconductor substrate, thereby driving said first microwave energy measurement apparatus; capturing, by said second microwave energy measurement apparatus, microwave energy passed through said semiconductor substrate, thereby driving said second microwave energy measurement apparatus; measuring said reflected microwave energy; measuring said passed through microwave energy; comparing said reflected microwave energy with said passed through microwave energy; and initiating intervention, by raising a visual or audible alarm invoking human or automatic intervention, if said reflected microwave energy exceeds said passed through microwave energy.