Secondary ion emission from solid surfaces irradiated with highly charged ions

We have observed positive secondary ion mass spectra from highly oriented pyrolytic graphite (HOPG) and hydrogen terminated Si (Si-H) surfaces irradiated with highly charged ions (HCIs). In the spectra from HOPG irradiated by HCIs of Xeq+, carbon clusters up to C5+ were observed in addition to hydrogenated carbon cluster peaks. On the other hand, in the spectra from the Si(1 1 1)-H, peaks of H+ and H2+ were detected dominantly with weak signals for C+ and Si+. Strong dependence of peak intensities of these spectra on q were also observed. It is shown that sputtering phenomena are closely related to deposition of potential energy of HCIs onto the surfaces and the HCI-probe can be applied to the high sensitivity surface analysis.