SURFACE CHARACTERIZATION OF EPITAXIAL, SEMICONDUCTING, FESI2 GROWN ON SI(100)

We have identified the composition and range of thermal stability of FeSi and FeSi2 films grown on Si(100) by solid phase epitaxy and reactive deposition epitaxy. Evidence for the semiconducting character of FeSi2 is obtained from photoemission measurements giving a low density of states at the Fermi level. Si enrichment at the outer surface of the silicides at temperatures much lower than previously thought has been found by depth profiling. Scanning tunneling microscopy reveals a rather inhomogeneous growth with a tendency towards epitaxial growth favored by the presence of surface steps on the Si substrate.