Growth of 4H and 6H SiC in trenches and around stripe mesas

Growth has been performed by vapor phase epitaxy on non-planar substrates in order to reveal growth habits in etched trenches and around stripe mesas. It was found that the growth habit is sensitive to variations in the C:Si ratio, rather than in temperature. At low C:Si ratio faceted growth occurs, mainly limited by surface reactions at the different growing planes, while at high C:Si ratio the growth habit is determined by gas phase diffusion and surface diffusion of the reactants. We could also show that the growth rate is about 20% higher in the [11 (2) over bar 0] than in the [1 (1) over bar 00] directions. The surfaces of growth on top of mesas have been studied by atomic force microscopy (AFM). Mesas along the off-cut direction shows hence a clear step flow growth, while perpendicular mesas show island formation. Scanning capacitance microscopy also shows a difference in net carrier concentration between a- and c-planes for Al doped layers grown around mesas.