Ab initio studies of early stages of AlN and GaN growth on 4H-SiC

Processes of aluminum and gallium adsorption on Si- and C-terminated 4H-SiC(0001) surfaces have been studied within the DFT framework. Al and Ga coverages ranging from a submonolayer to one monolayer have been considered. The results show that Al binds more strongly to both surfaces than Ga and the binding of both metals is stronger to the C-terminated than to Si-terminated surface of SiC. The lateral lattice sites occupied by Al and Ga atoms at one monolayer are different and it is due to a different charge transfer from metal to the substrate