Ion beam sputtering of germanium – Energy and angular distribution of sputtered and scattered particles

The energy and angular distributions of scattered and sputtered particles produced by ion beam sputtering of a Ge target under variation of geometrical (incidence angle of primary ions and emission angle of secondary particles) and ion parameters (ion species (Ar, Xe) and energy (0.5–1.5 keV) are presented. Several sets of Ge thin films are deposited and their thickness is measured by profilometry to determine the angular particle flux distribution of the sputtered particles. The particle flux distributions are of cosine-like shape and tilted in forward direction and the tilt of the maximum position increases with decreasing energy of the primary ions and increasing incidence angle. The energy distributions of the sputtered and the scattered ions are measured with an energy-selective mass spectrometer. The average energy of the sputtered ions increases with increasing incidence angle of the primary ions and with increasing emission angle, but is nearly unaffected by the species of the primary ions and their energy. The energy distribution of the scattered Ar ions reveals high energetic maxima that originate in direct scattering between Ar/Ge and Ar/Ar and which shift with increasing emission angle to higher energies. For Xe ion bombardment, there are only maxima for Xe/Xe scattering observed. All experimental data are compared with Monte Carlo simulations done with the well-known TRIM.SP code