ABSTRACT

The intense research efforts on the material and electronic properties of SiC is driven by the prospect of developing high-power and high-temperature electronic devices [1]. Improvements in the growth of single-phase SiC with reduced polytypes and the growth of doped epitaxial layers has accelerated the development of these devices. Technological challenges to be overcome include the formation of a high-quality insulating oxide layer that is critical to the deployment of SiC in metal-oxide-semiconductor (MOS) devices. The density of oxide-bulk interface states for SiC is about an order higher than for silicon and has been attributed to excess carbon at the interface [2]. Another interesting technological prospect involves the growth of heterostructures consisting of different polytypes of silicon carbide with band gaps differing as much as 1 eV These polytype structures differ in the Si-C stacking sequence along one direction, e.g., cubic 3C, hexagonal 2H (wurtzite), 4H, and 6H [3]. The most common hexagonal polytypes are 6H and 4H, where the 6 and 4 refer to the number of planes in the periodic stacking sequence. The growth of heterostructures of different SiC polytypes is interesting from the viewpoint of band gap engineering.