Angular distribution of sputtered matter under Cs+ bombardment with oblique incidence

Silicon, germanium and indium phosphide targets are sputtered with a cesium ion beam. The energy of impact is changed from 2 keV to 10 keV and the incidence angle of bombardment is modified from 30° to 60°. Emitted matter is collected on a semi-cylindrical copper foil. Subsequently, spatially resolved thicknesses and elemental compositions of the deposit are determined by means of SIMS depth profiles. These distributions across the deposit allow us to deduce the angular distribution of emitted matter. Our experimental data show that the preferential direction as well as the spreading around this direction can be altered, with more or less efficiency, by the variation of the bombardment parameters. For the indium phosphide, we also study the elemental composition of the deposit in function of the emission angle. It shows an increasing deviation from stoichiometry with increasing emission angle.