A study of preferred orientation of vanadium nitride and zirconium nitride coatings on silicon prepared by ion beam assisted deposition

Abstract

Vanadium nitride (VN) and zirconium nitride (ZrN) films were prepared by an ion beam assisted deposition (IBAD) method. The substrate temperature (150, 300 and 500°C), nitrogen ion beam energy (150–1000 eV) and incident angle (45 and 0°) were chosen as the processing variables. The ion sputtering/channeling effect and the energy input model can be used to explain the changes in preferred orientation of VN and ZrN. In VN we observed a change in preferred orientation from (111) to (200) at 300°C growth temperature with normal incident ion-beam energy of higher than 350 V. For ZrN films, 750 V was required to reach similar conditions. We also observed an increase in (200) by increasing the substrate temperature of VN to 500°C. An accelerated grain growth was formed, leading to a hillock-like surface topology in VN films grown at 500°C with 45° incident ion beam at 500 V acceleration voltage. This might be caused by an ion beam-assisted surface diffusion process. VN films with a completely (111)-oriented texture have been grown and an ion sputtering/channeling model is still used to elucidate the result.