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