Formation Mechanism and Complex Faulting Behavior of a BPD Loop in 180 μm Thick 4H-SiC Epitaxial Layer

4H-SiC with 180 μm epilayer was subjected to UV exposure. Stacking fault expanded from basal plane dislocation (BPD) loop generated during growth in the epilayer was observed by UV Photoluminescence Imaging (UVPL) and X-ray Topograph (XRT) techniques. Interactions between partial dislocation, emanating from the BPD loop and gliding via recombination-enhanced dislocation glide mechanism, and threading screw/mix dislocations are detected and analyzed, where stacking faults migrate to different basal plane after the interactions. Such migration increases the faulted volume that can severely degrade reliability and performance of high power SiC devices by increasing reverse leakage current and on-state resistance and could eventually lead to device failure.