Fast isotropic adatom diffusion on Ge(015) dot facets

Abstract

We investigate adatom self-diffusion on the rebonded step (RS) reconstructed Ge(105) surface. Activation energies for several paths are computed ab initio by applying the nudged elastic band method and used as input parameters for kinetic Monte Carlo simulations. We show that the RS reconstruction strongly influences adatom kinetics, which turns out to be fast at typical experimental temperatures, along both [010] and [501] directions. The influence of strain on diffusion is also investigated. Our results are shown to be relevant for a better understanding of the growth modality of Ge pyramids on Si(001). © 2004 The American Physical Society.