Overview and Latest Developments in Photoconductance Lifetime Measurements in Silicon

Photoconductance measurements have been one of the most common ways to measure the lifetime in silicon for over 60 years. Since 1985, the most common method for doing calibrated lifetime measurements is using an eddy-current sensor to monitor photoconductance as a function of time and illumination, providing data that can be interpreted in terms of carrier density and hence lifetime. Here we present recent extensions to this measurement technique that have generalized the method. Bulk lifetime measurements on industrial samples are presented. The information available from the effects of grain boundaries on eddy-current measurements are summarized. Recent applications for the use of these instruments for measurement of mobility in compensated materials are also described.