| Abstract: | The epitaxial growth of As on the (111) and (100) faces of Si and the (111) face of Ge has been studied with vacuum tunnelling microscopy. The (111) faces of both semiconductors display a principally 1×1 termination, but differ with the presence of point defects on the Si(111): As-1×1 surface and trenches separating large (～ 100 Å) domains on the Ge(111): As-1×1 surface. I-V characteristics of the tunnel junction show a surface energy gap of approximately 1·9 eV for the Si(111): As-1×1 surface and 0·9 eV for the Ge(111): As-1×1 surface, in good agreement with recent theoretical calculations for these systems. As deposition on Si(001) results in a nominal 2×1 reconstruction of symmetric As dimers and elimination of missing dimer defects characteristic of the native Si(001) 2×1 surface. Further studies on vicinal, double-stepped substrates shows the orientation of the dimers with respect to the substrate depends critically on the substrate temperature during the growth phase, with destruction of the single principle domain surface order occurring at temperatures in excess of 700°C. |
