Reducing the Wafer Off Angle for 4H-SiC Homoepitaxy

Abstract

We have investigated key factors for controlling the polytype and surface morphology of 4H-SiC homoepitaxial growth on less than 4o off-axis substrates. In addition, we characterized the crystal quality and surface quality of the epitaxial layer in whole 3-inch vicinal off angled substrate. The results suggested that the control of surface energy, control of the vicinal off angle itself, and high temperature growth, is highly important in controlling the surface morphology and polytype stability of the epitaxial layer grown on a vicinal off angled substrate. We also obtained a high-quality epitaxial layer grown on a 3-inch vicinal off angle substrate, which was comparable to those on 4o off-axis substrates. These results suggest that the wafer off angle for epitaxial growth can be reduced to less than 4 degrees.