Ion beam sputtering of ZnS thin films

Ion beam sputtering was used to deposit adherent high quality ZnS films non-reactively. The optical properties of films thicker than 80.0 nm were found to be equivalent to those of bulk ZnS with a packing density of unity. Unlike that of evaporated films, the refractive index was insensitive to the substrate temperature but for thinner films was dependent on the substrate condition prior to deposition. The deposition of fully dense films is qualitatively explained using Muller's model of ion-assisted deposition. In the case of ion beam sputtering, the high energy species comprise energetic sputtered atoms and/or molecules, reflected beam ions and charge exchange neutrals.