Characterization of comet-shaped defects on C-face 4H-SiC epitaxial wafers by electron microscopy

The crystallographic structures of comet shaped defects observed on the C-face 4H-SiC epitaxial film were investigated using electron microscopy. The comet shaped defects consist of head and tail parts. The tail part is symmetric with respect to the (1 (1) over bar 00) plane in the cross-sectional image and narrows along the [(11) over bar 20] direction, i.e., along the step flow direction of epitaxial film growth on the C-face. The tail part consists of four 3C domains with characteristic twin boundaries of Sigma 3 and Sigma 27. The head part is formed by 3C and defective hexagonal-SiC polycrystalline grains during epitaxial film growth. (C). 2015 Elsevier B.V. All rights reserved.