Photoemission spectroscopy of the evolution of ultra-thin Co films on Si(111) substrates upon annealing temperature

The evolution of the ultra-thin Co films on Si(lll) substrates upon anneali ng temperature in the range from room temperature to 800 degrees C was stud ied by means of photoemission spectroscopy (PES) with synchrotron radiation and low energy electron diffraction (LEED) techniques. 0.2-1.2 Ra. Co was evaporated onto Si(lll)-7 X 7 at room temperature. The behavior of the Go-s ilicon interfaces upon the annealing temperature was examined using Si 2p c ore level shifts and valence band measurements. The Si 2p core level spectr a were taken with the photon energy of 130 eV and we observed the core leve l shift upon the formations of CsCl-type CoSi and the CaF2 type CoSi2 as a function of annealing temperature and of the thickness of Co. We also estim ated the diffuse depth of Co depending on the annealing temperature. (C) 20 00 Elsevier Science B.V. All rights reserved.