Detection of latent scratches and swirl on silicon wafers by scanned surface photoresponse

Abstract

Latent scratches, surface effects, and swirl on silicon wafers can be nondestructively detected by the scanned surface photoresponse technique with results that are similar to those obtained with the usual destructive method of oxidation and preferential etching. In addition, scanned surface photoresponse can provide information on the depth of the damage related to latent scratches and surface effects by noting the effect of bias on the signals observed. The nondestructive nature of the measurement allows one to study phenomena which are not normally accessible such as the change in swirl patterns on a silicon wafer with heat treatment.