LeTID- and (Extended) BO-Related Degradation and Regeneration in B- and Ga-Doped Monocrystalline Silicon during Dark and Illuminated Anneals
Abstract
We study the degradation effects of boron-oxygen related light-induced degradation (LID) and light- and elevated temperature-induced degradation (LeTID) on both B- and Ga-doped Cz-Si wafers from the same industrial producer. The wafers of the two doping types were subjected to the same sample processing and degradation conditions. The studied conditions include dark anneal (DA) at 175°C and illuminated anneals at 75°C and either 1 or 0.1 sun eq. illumination intensity, which allow a good direct comparison of the influence of the dopant elements on the degradation effects. We find an atypical injection dependence of LeTID in the Ga-doped samples compared to the ""standard"" behavior in B-doped silicon. The Ga-doped samples degrade strongly only when the carrier injection is low. Degradation of Ga-doped samples during DA is only observed on long timescales, resulting in an injection-dependent lifetime dissimilar to LeTID-degraded Ga-doped samples and B-doped samples after both DA and LeTID. The results indicate that the dopants have a strong influence on the degradation behavior.
