TiN films fabricated by reactive gas pulse sputtering: A hybrid design of multilayered and compositionally graded structures

摘要

Reactive gas pulse (RGP) sputtering approach was used to prepare TiN thin films through periodically changing the N-2/Ar gas flow ratio. The obtained RGP-TiN film possessed a hybrid architecture containing compositionally graded and multilayered structures, composed of hcp Ti-phase and fcc TiN-phase sublayers. Meanwhile, the RGP-TiN film exhibited a composition-oscillation along the film thickness direction, where the Ti-phase sublayer had a compositional gradient and the TiN-phase retained a constant stoichiometric ratio of Ti:N approximate to 1. The film modulation ratio lambda (the thicknesses ratio of the Ti and TiN-phase sublayer) can be effectively tuned by controlling the undulation behavior of the N-2 partial flow rate. Detailed analysis showed that this hybrid structure originated from a periodic transition of the film growth mode during the reactive sputtering process. (C) 2016 Elsevier B.V. All rights reserved.