Turning of Basal Plane Dislocations during Epitaxial Growth on 4° Off-Axis 4H-SiC

Abstract

Epitaxial layers were grown on 4° off-axis 4H-SiC substrates by hot-wall chemical vapor deposition. The reduced off-cut angle resulted in lower basal plane dislocation (BPD) densities. The dependence of BPD reduction on growth conditions was investigated using ultraviolet photoluminescence (UVPL) imaging. With this method, it was found that the dislocations were converting to threading edge dislocations throughout the thickness of the film. A high (≥ 97%) conversion efficiency was found for all films grown with this orientation. A conversion of 100% was achieved for several films without pre-growth treatments or growth interrupts.