RBS-ERDA, XPS and XRD characterizations of PECVD tungsten nitride films
Résumé
Tungsten nitride thin films are synthesized by plasma enhanced chemical vapor deposition using a hot wall type reactor. Amorphous and nanocrystalline W and W-N:H thin films are obtained in the temperature range 250-620°C with a plasma generated by a low frequency generator. Feed gases used are WF,, NH-,, Ar and H,. Amorphous tungsten nitrides can be obtained at 250°C without hydrogen in the plasma. The surface is examined by atomic force microscopy (AFM) in order to evaluate growth conditions on silicon (100) substrate. Elastic recoil detection analysis indicates that the hydrogen content is about 16% at the surface and 10% at the silicon-film interface. XRD analysis show a tungsten or tungsten nitride crystallographic form for the films analyzed.