We have observed dominant epitaxial growth of Al(100) films on chemically cleaned, hydrogen terminated, off-oriented Si(111). The films were deposited by thermal evaporation at room temperature in ultrahigh vacuum. X-ray diffraction shows sharp and intense Al(200) diffraction, enhanced by postdeposition annealing. Crystal quality and the dominance of Al(100) structure depend strongly on the substrate treatment and the off-cut angle, both of which control the steps on the Si(111) surface. The steps were found responsible for the epitaxial alignment of the film and the substrate lattices. Details of this alignment were observed in transmission electron microscopy cross-sectional images of the interface. Our findings are in contrast to previously published results which indicate epitaxial growth of Al(111) on Si(111).
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)