Reconstruction-determined diffusion of Ag adatoms on the Si(111)-(7x7) surface

Surface diffusion is one of the basic processes determining morphology of a growing film. In the case of metal heteroepitaxy on Si (I I 1)-(7 x 7) the diffusion is strongly affected by the presence of surface reconstruction, which introduces additional constraints into the motion of deposited atoms. To determine diffusion parameters we used two different approaches: i) interpretation of experimentally observed morphologies by a coarse-grained kinetic Monte Carlo model, ii) direct observation of adatom movement using UHV STM. The attempt frequency and the barrier to hopping of a single Ag atom between half-unit cells of the reconstruction were estimated in both cases. Obtained values are compared and discussed.