Patent ID: 7190186
Filing Date: 2007-03-13
Classification: G01R

Abstract:
1. A method of determining a concentration of defects and/or impurities in a semiconductor wafer comprising: (a) providing a semiconductor wafer having a substrate of semiconducting material; (b) forming an electrical contact with a top surface of the semiconductor wafer; (c) causing a first current value to flow in the semiconductor wafer via the electrical contact; (d) exposing the semiconductor wafer under or adjacent the electrical contact formed in step (b) to light whereupon a second current value flows in the semiconductor wafer; (e) terminating the light; (f) determining a rate of change of the current from the second value toward the first value; and (g) determining a concentration of defects and/or impurities in the semiconductor wafer as a function of the rate of change determined in step (f).