Cesium Ion Sputtering With Oxygen Flooding: Experimental Sims Study Of Work Function Change

摘要

We investigated the work function (WF) change of a silicon surface being under cesium ion bombardment and simultaneous oxygen flooding with various oxygen pressures at the sample surface. It was found that WF of Cs~+ ion sputtered Si decreases under oxygen flooding. This decrease provides an essential grow of secondary ion yields of some negative ions, sputtered from Si. At the same time Si~- ion yield decreases approximately in two times. In the paper we have discussed possible explanations of our experimental data: we considered a surface composition change, formation of surface dipoles and work function change caused by oxygen adsorption, and their relationships between each other.