Secondary ion emission from a water and fluorine adsorbed Si(100) surface irradiated with electrons and highly charged ions

Secondary ion emission phenomena from a water and fluorine adsorbed Si(1 0 0) surface irradiated with electrons and highly charged ions (HCIs) were studied. In the case of HCI impact (400 eV/q Arq+ 4 less than or equal to q less than or equal to 8), H+ and F+, ions were detected in addition to Si(H)(+) and SiOH+ ions resulted from a kinetic energy transfer. The yields of H+ and F+, which were also observed in the case of electron impact, increased with q like q(gamma) (gamma similar to 3). This is the first paper reporting a strong charge state dependence of heavy adsorbate yields when slow HCIs bombard a well-defined surface covered with adsorbate. (C) 2003 Elsevier Science B.V. All rights reserved.