Decay kinetics of two-dimensional islands and holes on Si(111) studied by low-energy electron microscopy

Low-energy electron microscopy was used to study the decay kinetics of two-dimensional islands and holes with diameters of a few micrometers to similar to 100 nm on Si(111) near the "1x1'' to 7x7 phase-transition temperature. It is shown that the decay is governed by the diffusion of adatoms rather than the attachment/detachment of atoms at steps. The comparison between the island and hole decays gives an upper limit for the Ehrlich-Schwoebel barrier. We also show that the surface mass diffusion constant on 7x7 is smaller than that on "1x1".