Step bunching of vicinal 6H-SiC{0001} surfaces

We use kinetic Monte Carlo simulations to understand growth-induced and etching-induced step bunching of 6H-SiC{0001} vicinal surfaces oriented toward < 1 (1) over bar 00 > and < 11 (2) over bar0 >. By taking account of the different rates of surface diffusion on three inequivalent terraces, we reproduce the experimentally observed tendency for single bilayer height steps to bunch into half unit-cell height steps. By taking account of the different mobilities of steps with different structures, we reproduce the experimentally observed tendency for adjacent pairs of half unit-cell height steps to bunch into full unit-cell height steps. A prediction of our simulations is that growth-induced and etching-induced step bunching lead to different surface terminations for the exposed terraces when full unit-cell height steps are present.