Epitaxial growth of 4H-SiC layers on 4H-SiC vicinal off-cut substrates for GaN/SiC hybrid devices

An AlGaN/GaN HEMT structure was successfully grown on a 4H-SiC epitaxial wafer with a 0.5 o off-cut 4H-SiC substrate to realize SiC/GaN hybrid devices. By modifying the 4H-SiC epitaxial growth process, for example by eliminating the in-situ H 2 etching process or applying H 2 annealing after epitaxial growth, we could effectively suppress the generation of significant step bunching on a 4H-SiC epitaxial layer surface. As a result, a high quality 4H-SiC epitaxial layer with good surface morphology and ideal blocking voltage characteristics of 600 V, could be grown on a 0.5 o off-cut 4H-SiC substrate. A high quality AlGaN/GaN HEMT structure could also be heteroepitaxially grown on this grown 4H-SiC epitaxial layer for the first time. The surface roughness and C-V characteristics of the AlGaN layer were significantly improved by reducing the wafer off-cut angle of the 4H-SiC epitaxial layer from 4 to 0.5°. These results are the first to indicate that a high quality AlGaN/GaN HEMT structure and a 4H-SiC homoepitaxial layer can be multi-epitaxially grown on a 0.5 o off-cut 4H-SiC substrate. The realization of GaN/SiC hybrid devices can be strongly expected. • Surface morphology of an 0.5 o off 4H-SiC epitaxial layer was improved. • Nitride layers was heteroepitaxially grown on an 0.5 o off 4H-SiC epitaxial wafer. • High quality nitride and 4H-SiC epitaxial layers could be grown. • The realization of GaN/SiC hybrid devices can be strongly expected.