Neutral copper cluster sputtering yields: Ne(sup +), Ar(sup +) and Xe(sup +) bombardment.

摘要

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 dependence on the total sputtering yield.