Influence of the facet trace region in 4H-SiC substrate on the glide and propagation behaviors of basal plane dislocations in 4H-SiC homoepitaxial layers

The influence of the facet trace region in the 4H-SiC substrate on the glide and propagation behaviors of basal plane dislocations (BPDs) in a 4H-SiC homoepitaxial layer was investigated using x-ray topography, high-resolution x-ray diffraction, and micro-Raman scattering spectroscopy. The facet trace region in the substrate, which has a higher nitrogen doping concentration than the other regions in the substrate, is of great interest since it could influence the glide and propagation behaviors of BPDs during 4H-SiC homoepitaxial growth through enhanced nitrogen doping concentration in the region. It was found that the epitaxial layer grown on the facet trace region in the substrate significantly suppressed glide motion of BPDs and exhibited a reduced conversion probability of BPDs to threading edge dislocations during the homoepitaxial growth process. Based on these results, the mechanisms that the epilayer grown on a substrate region with a slightly higher nitrogen concentration showed significantly different glide and propagation behaviors of BPDs are discussed.