Effects of HCl-H/sub 2/ pre-growth etching on quality of 6H-SiC epitaxial layers

The correlation between the HCl-H/sub 2/ pre-growth etching of 6H-SiC substrates and the electrical characteristics of Schottky barrier diodes on the epitaxial layers has been investigated. The morphology of 6H-SiC (Si-face) off-axis substrates and the subsequent epitaxial layers was changed by the etching. Electrical measurements revealed that the impurity concentration of the epitaxial layers and the diode characteristics were affected by the pre-growth etching. It was shown that the leakage current of the diode could be reduced to 5/spl times/10/sup -/8 A/cm/sup 2/ (at 200 V) by optimizing the etching.