ION IMPACT DESORPTION OF METAL ATOMS FROM SI(111)-SQUARE-ROOT-3 X SQUARE-ROOT-3-METAL SURFACES

The cross-sections for desorption and recoil-implantation of Ag and Au at the Si(111)-square-root 3 x square-root 3 -metal surfaces by keV Ar+ ions have been measured by means of LEED, AES and RBS techniques to determine their surface binding energy. The concentration decay of metal atoms at the Si(111)-square-root 3 x square-root 3 -metal surfaces has been measured by means of AES and RBS techniques as a function of Ar+ fluence. From the concentration decay profiles, the cross-sections for desorption and recoil-implantation are determined as functions of Ar+ energy. It is determined that the surface binding energies of Ag and Au are 0.6 eV and 2.7 eV, respectively, by fitting the calculated recoil-production cross-sections to the experimental recoil-implantation cross-sections. Both cross-sections are discussed in comparison with the sputtering cross-section of the substrate.