First stages in the formation of ultra thin nickel layers on Cu 111/ and Ge 111/ and dissolution: an AES comparative study

In this paper we present a low energy electron diffraction LEED.–Auger electron spectroscopy AES.comparative study of slow deposition of nickel vapor onto clean Cu 111.and Ge 111.substrates at room temperature and dissolution of the as-deposited ultrathin Ni layers at higher temperature. The main results of the present investigation are: i. the growth of nickel on Cu 111.occurs via a layer-by-layer or a simultaneous multilayers growth mode and epitaxial pseudomorphic Ni layers are obtained in agreement with previous studies, and ii. the growth of nickel on Ge 111. is described considering the partial formation of a surface compound andror Ge surface segregation during deposition. Annealings of the as-deposited Ni layers confirm these results: when the mass transport is high enough a complete dissolution of nickel in copper is observed while superficial nickel germanide formation is obtained on germanium according to the phase diagrams of the systems. q2000 Elsevier Science B.V. All rights reserved.