Potential sputtering of target ions by Ar^q+, Pb^q+ projectiles from a silicon surface

Highly charged ions have been expected to be a powerful tool for the surface modification in nano-scale. The potential sputtering of highly charged ions on semi-conductors has the potential to be applied in the micro electronics and nano-technology. In this work, the Ar^q+ and Pb^q+ ions produced by an electron cyclotron resonance ion source have been used as projectiles to study their potential sputtering on silicon surface. The relative sputtering ion yield is measured with a micro-channel plate, correlated to the incidence angle, charge state and velocity of ions. The experimental results show evidently charge dependence and velocity dependence. The yield induced by the ions changes steeply with the incidence angle, which is much larger than the impact of single charged ion with the same velocity. In the case of Pb³⁶⁺ impact, a significant enhancement of the yield has been observed, while the q > 20. At the same time, the yield increases proportionally with the ion velocity. However, in the case of Ar¹⁶⁺, the yield decreases versus the increase of the velocity.