SPUTTERING OF GOLD AND COPPER SURFACES UNDER LOW ENERGY CESIUM IONS

To use gold and copper ions for ion implantation through 1-MV pelletron accelerator, gold and copper targets were bombarded with low energy cesium ions applying source of negative ions by cesium sputtering (SNICS). This work aims to investigate the cluster dynamics of these noble metals in a low energy range so that optimized data can be obtained for the use of these cluster ions in ion implantation. Negative ions including monomers and clusters of both metals were detected which were mass analyzed. Cu clusters up to Cu-4(-1) and gold clusters up to Au-7(-1) were emitted. The minimum energy of cesium ions to produce enough cluster ions so that they could be detected by a mass analyzer has been determined. The data was analyzed to measure sputtering yield, total sputtering yield and normalized number density of different sputtered species. In this energy range, the sputtering behaviors of Cu remain almost constant but in the case of Au there is a slight increase in cluster sputtering probability with an increase in incident ion energy. The sputtering yield of clusters decreases according to the power-law, i.e. y(n)proportional to n(-delta). Power law exponent in the case of copper has an average value of similar to 2.3 whereas exponent in the case of gold clusters changes from 3.5 to 6.

Automated summary

This study investigates the cluster dynamics of gold and copper ions in a low energy range through bombardment of gold and copper targets with low energy cesium ions. The results show that the sputtering behavior of copper remains constant, while the cluster sputtering probability of gold clusters slightly increases with an increase in incident ion energy.