Electronic and chemical passivation of hexagonal 6H-SiC surfaces by hydrogen termination

Hydrogenation of 6H-SiC (0001) and (000(1) over bar) is achieved by high-temperature hydrogen treatment. Both surfaces show a low-energy electron diffraction pattern representative of unreconstructed surfaces of extremely high crystallographic order. On SiC(0001), hydrogenation is confirmed by the observation of sharp Si-H stretching modes. The absence of surface band bending for n- and p-type samples is indicative of electronically passivated surfaces with densities of charged surface states in the gap of below 7 x 10(10) cm(-2) for p-type and 1.7 x 10(12) cm(-2) for n- type samples, respectively. Even after two days in air, the surfaces show no sign of surface oxide in x-ray photoelectron spectroscopy. (C) 2001 American Institute of Physics.