Highly Reliable 4H-SiC Epitaxial Wafer with BPD Free Recombination-Enhancing Buffer Layer for High Current Applications

Abstract

Epitaxial growth of 4H-SiC on 150 mm wafers with the recombination-enhancing buffer layer was studied. In order to accomplish the reduction of basal plane dislocations in the buffer layer to almost free level and assure its quality in production, non-destructive evaluation using photoluminescence method was investigated. Epitaxial wafers of which the buffer layer and the drift layer have more than 99% BPD free area in a 2.6 mm × 2.6 mm block evaluation were realized by optimizing the epitaxial growth conditions. Furthermore, very low surface defects density and excellent thickness and doping uniformity were achieved simultaneously.