Neutral copper cluster sputtering yields: Ne{sup +}, Ar{sup +} and Xe{sup +} bombardment

The sputtering of neutral metal clusters was investigated by measuring relative sputtering yields of copper clusters ejected from polycrystalline copper under 3.9 keV bombardment by Ne{sup +}, Ar{sup +} and Xe{sup +} ions at normal incidence. Yields of clusters from Ne{sup +} bombardment were lower than those from Ar{sup +} bombardment, were lower than from Xe{sup +} bombardment. Sputtering yield ratios Ne{sup +}/Ar{sup +} and Xe{sup +}/Ar{sup +} were 0.56 and 1.08. Size distribution of sputtered clusters can be fit by a power law dependence with exponents of {minus}8.1, {minus}8.2 and {minus}6.2 for Ne{sup +}, Ar{sup +} and Xe{sup +}, respectively. The similarity of the exponents of the Ne{sup +} and Ar{sup +} power law fits indicates that the sputtering yields for these two primary ions are similar while that for Xe{sup +} is substantially higher, in contrast to the sputtering yield ratio data. The difference between the two measurements can be explained by assuming a systematic uncertainty in the sputtering yield ratio measurements that makes the measured ratios lower than the true values. Assuming a value at the high end of the experimental Ne{sup +} sputtering yield range, the exponents of the power law fits exhibit a linear dependencemore » on the total sputtering yield.« less