Surface topography and thin film growth.

Abstract

The correlation of surface topography with the growth of metal thin films is reviewed. UHV-cleaved surfaces of ionic crystals such as NaCl, KCl, KBr, and MgO have fine structures distinguished in six characteristic zones : (1) Starting zone; (2) V-zone; (3) transition zone; (4) tartan zone; (5) stop-band zone; (6) restarting zone. Epitaxy, non-epitaxy, and graphoepitaxy of Sn are strongly influenced by these surface zones of the NaCl and KCl substrates. In the case of Au films, structural changes as well as morphological changes occur at the steps of the NaCl substrate. In addition, for Au/NaCl, quantitative results by the discrete variational Xα cluster method are indicated. On the other hand, the graphoepitaxy proposed first by H.I. Smith and co-workers is characterized by “epitaxial” growth on amorphous substrates having artificially produced surface-relief structures. Some experiments concerning graphoepitaxy are introduced.