Minority Carrier Lifetime Properties of Reactive Ion Etched p-Type Float Zone Si

Abstract

Quasi-steady-state photoconductance (QSSPC) and deep level transient spectroscopy (DLTS) were used to characterize the minority carrier lifetime properties of reactive ion etched p-type Si. The effective lifetime of the plasma-processed samples degraded after etching, with the densities of recombination centers increasing linearly with etch time. Evidence is provided for the long-range (> 2 μm) migration of defects in the plasma-etched samples. A discrete defect with energy position at (0.32 ± 0.02) eV, that could be either B- or H-related, was detected by DLTS in the etched samples. Furthermore, this energy level could be used to adequately model the injection-dependence of the measured carrier lifetimes using the Shockley-Read-Hall model. Our results show that DLTS and QSSPC is a powerful combination to characterize the electrical properties of defects that are relevant to the performance of solar cells.