Step bunching of vicinal6H-SiC{0001}surfaces

Abstract

We use kinetic Monte Carlo simulations to understand growth-induced and etching-induced step bunching of $6H\text{-SiC}{0001}$ vicinal surfaces oriented toward $⟨1\overline{1}00⟩$ and $⟨11\overline{2}0⟩$. 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.