Ordered growth of Ge islands above a misfit dislocation network in a Ge layer on Si(111)

A flat Ge layer on Si(lll) with a buried dislocation network at the Si/Ge i nterface is used as substrate. This flat Ge film was grown with Sb as surfa ctant. During subsequent growth and coarsening of two-dimensional Ge island s, ordering of the islands with respect to the underlying dislocation netwo rk (which has a periodicity of similar to 100 Angstrom) is observed using s canning tunneling microscopy (STM). During coarsening, preferred growth of the islands occurs near the minima of the height undulations induced by the buried dislocation network. This ordering effect is explained by strain in duced preferred diffusion towards these areas and energetically favorable b inding at these positions above the dislocations. (C) 2000 Elsevier Science B.V. All rights reserved.