Energetics of the surface step and its morphology on the 3C-SiC(111) surface clarified by the density-functional theory

Abstract

We report first-principles calculations that clarify the atomic structures and the energetics of all the possible atomic steps on 3C-SiC(111) surfaces. The calculated formation energies of the atomic steps reveal the origin of the experimentally observed variation of the step morphology, i.e., the emergence of either the straight or the meandering step edge, depending on the inclined direction of the vicinal SiC surfaces. We find that the peculiar reconstructions near the steps play decisive roles in the step energetics. The calculated formation energy of the meandering step edge shows that the straight step edges along particular directions are energetically unfavorable.