Defect Propagation from 3C-SiC Intermediate Layers to III–Nitride Epilayers

The propagation of crystal defects from a 3C-SiC intermediate layer (3C-SiC IL) to hexagonal III–nitride epilayers formed by a metalorganic vapor phased epitaxy (MOVPE) has been investigated by observing the interface between the 3C-SiC IL and the hexagonal III–nitride epilayers. The 3C-SiC(111) IL grown on a Si(111) substrate has many stacking faults (SFs) that form along the 3C-SiC111 planes. The density of the SFs decreases with separation from the Si substrate. The initial III–nitride epilayers have V-shaped trenches due to the SFs of the 3C-SiC IL. However, there are some SFs, that do not generate V-shaped trenches. On the basis of high-resolution cross-sectional observations by transmission electron microscopy and X-ray pole-figure analysis, an atomic model for the SFs is considered in terms of twin bands of 3C-SiC. V-shaped trenches were determined to be formed on protrusions consisting of the twin bands in the 3C-SiC IL.