Influence of ion induced surface defects on the nucleation and formation mechanisms of metallic thin films

Using an in situ ultra high vacuum (UHV) electron tunneling microscope, we have studied the influence of ion induced defects on highly oriented pyrolitic graphite on metallic thin film formation. The impact of ions with energy ranging from 10 to 300 eV induces several kinds of defects on the substrate surface. We classified defects according to impinging energy of ions and this correlates well with atomic resolution images of bombarded surfaces. More precisely, we will present here the influence of these defects on the initial formation of nickel and molybdenum thin films. We have analyzed thin films deposited by both direct ion beam and electron beam evaporation. We reveal clear differences and prove the dramatic influence of surface defects on the nucleation of thin films. These investigations have specific importance for the control and production of materials enclosing metallic and semiconducting nanoparticles used in a new generation of magnetic and optoelectronic devices. (C) 2000 Elsevier Science S.A. All rights reserved.