Single-Domain 3C-SiC Epitaxially Grown on 6H-SiC by the VLS Mechanism

Abstract

Using the Vapor-Liquid-Solid mechanism in Ge-Si melts we have grown 3C-SiC layers on top of <0001>-oriented, Si face, 6H-SiC substrates. The surface morphology was free of spiral growth but highly step bunched. The 3C-SiC polytype was identified by micro- Raman spectroscopy and confirmed by low temperature photoluminescence. Electron backscattering diffraction mapping showed that the upper side of the layers is single-domain, i.e. that the 3C-SiC material displays only one in-plane orientation. Cross-sectional and planeview TEM investigations allowed detection of double positioning boundaries but only confined at the substrate/epilayer interface. The main additional defects found were stacking faults (SF) with a density of ~ 4.103 cm-1. Forming at the interface, they propagate through the epitaxial layer.