Impact of LeTID in Industrial P- and Sb-Doped n-Type Cz-Si With Melt Recharging

Abstract

In this study the impact of treatments under illumination at elevated temperatures on the long-term stability of excess carrier lifetime in state-of-the-art melt recharging Czochralski-grown silicon with n-type dopants is investigated. For samples that are treated at elevated temperatures and illumination only, it is found that bulk regeneration dominates until surface related degradation becomes limiting. If an additional light-soaking treatment at room temperature is previously applied, both bulk degradation and regeneration can be observed for P- and Sb-doped Cz-Si. An increase in degradation extent is observed for subsequently pulled ingots which is very similar for both dopant species. It is therefore assumed that the accumulation of impurities in n-type Cz-Si may be involved in an increase of defects that form during treatment at elevated temperatures and illumination. Furthermore, it is shown for Sb-doped material that the applied high temperature processing steps do not have an impact on degradation extent or kinetics.