Minority Carrier Diffusion Length Improvement in Czochralski Silicon by Aluminum Gettering

Abstract

AbstractGettering is widely used for fabricating integrated circuits using Si substrates, and has great potential for solar cell fabrications as well. Recently available solar cell efficiency studies have shown the benefits of the wafer backside Al, attributable to effects of gettering, a wafer backside field, and passivation of grain boundaries and dislocations. In this paper, we report experimental results which showed unambiguously that Czochralski Si wafer bulk minority carrier diffusion lengths can be significantly improved due to gettering of impurities by wafer backside Al, which also provided a protection from environmental contamination.