Published online by Cambridge University Press: 10 February 2011
We have investigated adsorption and diffusion processes of a Si atom on hydrogen-terminated Si(001)-(2×1) surfaces using first-principles total-energy calculations. The Si adatom segregates H atoms from surface Si dimer atoms on the monohydride terminated Si(001) surface. The migration of the Si adatom is assisted by the mobility of H atoms, that is, the Si adatom migrates on the surface by repeating release and capture of H atoms. The effects of a single H-terminated Si dimer on the Si migration are also examined. Calculated results are in good agreements with the variation in morphology of Si homoepitaxial films induced by hydrogen termination.