Minority carrier lifetimes in Cz-Si wafers with intentional V-I transitions

Abstract

A p-type Cz-Si crystal has been pulled with varying pulling speed in order to produce wafers containing two distinct regions; A region with silicon self-interstitial defects, and a vacancy dominated region. Band-to-band photoluminescence imaging has been used to study the minority charge carrier lifetimes in these wafers after different processing steps. Despite the different defects found in the different regions of the wafers carrier lifetimes appear to be uniform across the entire wafers, both for ungettered and gettered samples. Only after an oxidation process at 1100 °C oxygen related ring patterns become visible. It is, however, difficult to identify the band structure of the transition area between the regions among all the striations in the crystal.