Monitoring tantalum nitride thin film structure by reactive RF magnetron sputtering: Influence of processing parameters

•Monitoring of the structure of tantalum nitride thin films onto WC-6%Co using reactive RF magnetron sputtering•Influence of process parameters on the stabilization of both hexagonal TaN to face centered cubic TaN structures•Possible mechanism responsible for TaN structure stabilization considering adatom mobility on the substrate surface

Tantalum nitride thin films were deposited onto WC-6%Co substrates using reactive RF magnetron sputtering. Their structure and microstructure were studied and analyzed according to processing parameters. It has been demonstrated that the weight ratio of hexagonal TaN (h-TaN) to face centered cubic TaN (fcc-TaN) strongly depends on adatoms mobility on the substrate surface. In particular, growth conditions promoting adatoms mobility, i.e. low N2 partial pressure, total gas pressure, target-to-substrate distance as well as high target power density, promote the formation of h-TaN structure. Both exclusively fcc-TaN and exclusively h-TaN films were synthesized. A possible mechanism for the stabilization of those structures is discussed.