SIMPLIFIED AC PHOTOVOLTAIC MEASUREMENT OF MINORITY-CARRIER LIFETIME IN CZOCHRALSKI-GROWN SILICON-WAFERS HAVING RING-DISTRIBUTED STACKING-FAULTS

A simplified ac photovoltaic method is proposed for rapid measurement of minority carrier lifetime. It is used for lifetime distribution mea surement in a Czochralski-grown silicon wafer having ring-distributed stacking faults. A ring-distributed short-lifetime region was observed which corresponded to the stacking fault ring detected by X-ray topog raphy. In addition, a ring-shaped region where the lifetime is longer than 100 mus was observed for the first time outside the short-lifetim e region. This long-lifetime region could not be detected by X-ray top ography.