Lattice accommodation of epitaxial Bi(111) films on Si(001) studied with SPA-LEED and AFM

The growth of Bi on a Si(001) surface is studied in situ by spot profile analyzing low-energy electron diffraction and ex situ by atomic force microscopy. A continuous epitaxial Bi(111) film with a thickness of 6 nm is grown at 150 K in a bilayer growth mode. During annealing to 450 K the lattice mismatch between Si(001) and Bi(111) is accommodated by a periodic interfacial misfit dislocation array. On this relaxed template, Bi(111) films can be grown to any desired thickness. Such films are composed of twinned and 90 degrees rotated micrometer sized Bi(111) crystallites with a roughness of less than 0.6 nm for a 30 nm thick film.