Characterization of the fluxes of neutral and positively charged clusters (Agn and Ag+n; n≤4) produced by argon ion sputtering of silver

Abstract

The emission of neutral and positively charged silver clusters during sputtering of a polycrystalline silver target by 5 keV Ar + ion bombardment has been studied and the sputter ejected silver flux has been characterized. As a result, the silver flux is found to be strongly dominated by neutral clusters rather than cluster ions. The contribution of neutral clusters in the overall silver flux decreases rapidly and monotonically with increasing cluster size n and decreases, in addition, with decreasing bombarding energy. The well known alternation of the secondary ion intensities of Agn + as a function of cluster size (higher intensities for odd n) is found to be correlated with the effective "ionization potentials" of the corresponding sputtered neutral clusters.