Super-V-shaped structure on 3C-SiC grown on the C-face of 4H-SiC

We investigate a unique super-V-shaped structure (SVSS) on the C-face of 3C/4H-SiC heteroepitaxial films. Atomic force microscopy (AFM) and optical images reveal that two low protruding straight lines of an SVSS join at a common higher protruding point. Transmission electron microscopy images determine that the protruding point is induced by polycrystalline nucleation, and straight lines are found to be 3C crystals without any specific defects. High-resolution AFM reveals that the directions of the SVSSs are strongly related to step-flow. It is believed that the straight lines are caused by redundant adatoms gathering and crystallizing when they meet and deviate around the protruding point defect on their original migration path. The effects of step-flow and anti-step-flow in the formation of SVSSs are discussed. (paper)