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

Publication date: 15 April 2015
Source:Journal of Crystal Growth, Volume 416
Author(s): T. Yamashita , H. Matsuhata , T. Sekiguchi , K. Momose , H. Osawa , M. Kitabatake
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 $(1\overline{1}00)$ plane in the cross-sectional image and narrows along the $\left[\overline{1}\overline{1}20\right]$ 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 Σ3 and Σ27. The head part is formed by 3C and defective hexagonal-SiC polycrystalline grains during epitaxial film growth.