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

Abstract

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 $6\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ is grown at $150\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ in a bilayer growth mode. During annealing to $450\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ 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\ifmmode^\circ\else\textdegree\fi{} rotated micrometer sized Bi(111) crystallites with a roughness of less than $0.6\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ for a $30\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ thick film.