Influence of Carbon Source on the Buffer Layer for 4H-SiC Homoepitaxial Growth.

In this study, we systematically explore the impact of C/Si ratio, pre-carbonization time, H etching time, and growth pressure on the buffer layer and subsequent epitaxial layer of 6-inch 4H-SiC wafers. Our findings indicate that the buffer layer's C/Si ratio and growth pressure significantly influence the overall quality of the epitaxial wafer. Specifically, an optimal C/Si ratio of 0.5 and a growth pressure of 70 Torr yield higher-quality epitaxial layers. Additionally, the pre-carbonization time and H etching time primarily affect the uniformity and surface quality of the epitaxial wafer, with a pre-carbonization time of 3 s and an H etching time of 3 min found to enhance the surface quality of the epitaxial layer.