A LOW-TEMPERATURE ION VAPOR-DEPOSITION TECHNIQUE FOR SILICON AND SILICON-GERMANIUM EPITAXY

Ion beam vapor deposition is a new technique to grow Si and SiGe layer s on Si substrates at low temperatures. The growth of Si and SiGe laye rs reported in this paper involves ion-assisted dissociation of SiH4 i nto Si and H-2 where Si is deposited. The Ge incorporation is achieved through thermal co-evaporation of elemental Ge. The SiGe films deposi ted at temperatures below 350 degrees C are planar and epitaxially gro wn, as confirmed by Rutherford back scattering, transmission electron microscopy, and electron diffraction analysis. The in situ cleaning is achieved by Ar ion bombardment followed by an in situ thermal anneali ng to repair the damage. Polycrystalline SiGe films are also deposited on substrate surfaces coated with a thin oxide.