MBE growth and properties of SiC multi-quantum well structures

Multi-quantum well structures with 3C–SiC wells between α-SiC barriers were grown in a two-step procedure by solid-source molecular beam epitaxy. First, one-dimensional wire-like 3C–SiC was nucleated selectively on terraces of the well-prepared off-axis α-SiC(0 0 0 1) substrates at low temperature (T<1500 K). Next, 3C–SiC lamellae were incorporated into the hexagonal layer material via simultaneous step-flow growth mode of both the 3C–SiC nuclei and the hexagonal substrate material at higher T and Si-rich conditions. In comparison to homopolytypic SiC layers, photoluminescence investigations revealed additional signals, which can be explained by optical transitions within the thin cubic well layers.