Observation of surface modification and secondary particle emission in HCI-surface interaction

We have observed secondary particle emission in collision of HCI with Si and HOPG surfaces. For HOPG, we have measured the number of secondary electrons and the number of dot structures on the surface as the imprint of the incidence by STM. The single ion impact is surely observable with almost 100% efficiency by detecting an event of the secondary electron emission. For hydrogen terminated Si(1 1 1), H+, H2+, H3+, C+ and Si+ ions have been detected. The proton sputtering yield, which depends on the charge of HCI, has been examined.