YIELDS OF SPUTTERED METAL-CLUSTERS - THE INFLUENCE OF SURFACE-STRUCTURE

Sputtered neutral In(n) clusters generated by 4-keV Ar+ ions impinging onto an indium surface were investigated by single photon ionization and time-of-flight mass spectrometry. The distribution of the cluster sputtering yields as a function of the cluster size, n, was determined for various states of the sample surface. First, spectra taken on a s olid and a liquid indium surface were compared to investigate the role of crystal structure. Second, the influence of surface microroughness was studied by comparing spectra taken on a freshly molten and re-sol idified surface to those taken after prolonged ion bombardment. It is found that neither the crystal structure nor the surface topography pl ay a significant role in cluster sputtering.