Size distribution of sputtered particles from Au nanoislands due to MeV self-ion bombardment

摘要

Nanoisland gold films, deposited by vacuum evaporation of gold onto Si(100) substrates, were irradiated with 1.5 MeV Au~(2+) ions up to a fluence of 5 X 10~(14) ions cm~(-2) and at incidence angles up to 60° with respect to the surface normal. The sputtered particles were collected on carbon-coated grids (catcher grid) during ion irradiation and were analyzed with transmission electron microscopy and Rutherford backscattering spectrometry. The average sputtered particle size and the areal coverage are determined from transmission electron microscopy measurements, whereas the amount of gold on the substrate is found by Rutherford backscattering spectrometry. The size distributions of larger particles (number of atoms/particle, n ≥ 1000) show an inverse power law with an exponent of ～-1 in broad agreement with a molecular-dynamics simulation of ion impact on cluster targets.