Toward over unity proton sputtering yields from a hydrogen-terminated Si(111) 1×1 surface irradiated by slow highly charged Xe ions

Abstract

The emission of sputtered ions from a hydrogen-terminated Si(111) 1×1 surface has been measured for impact of slow (v<0.25vBohr) highly charged Xe ions. Proton sputtering yields increase strongly with projectile charge q (qγ;γ∼4) and reach to the value greater than one for Xeq+ impact (q≧44). Yields of Si+ remain constant (∼0.1) for lower q (14≦q≦29) but increase with q for higher q region which shows that the apparent Coulomb explosion-like potential sputtering might set in and enhances the sputtering yield drastically over q=29.