First-principles total-energy calculations were presented which provided a detailed picture of the adsorption and diffusion of a Si adatom on hydrogenated Si(100) surfaces. It was found that that the adatom spontaneously substituted for the H atom upon adsorption. It was also found that the pathways and barriers of adatom diffusion were sensitive to the H coverage. The calculated results were consistent with observed H-induced variations in the morphology of over-layers during epitaxial growth.

Adsorption and Diffusion of Si Ad-Atoms on Hydrogenated Si(100) Surfaces. S.Jeong, A.Oshiyama: Physical Review Letters, 1997, 79[22], 4425-8