RBS-ERDA, XPS AND XRD CHARACTERIZATIONS OF PECVD TUNGSTEN NITRIDE FILMS

Tungsten nitride thin films are synthesized by plasma enhanced chemica l vapor deposition using a hot wall type reactor. Amorphous and nanocr ystalline W and W-N:H thin films are obtained in the temperature range 250-620 degrees C with a plasma generated by a low frequency generato r. Feed gases used are WF6, NH3, Ar and H-2. Amorphous tungsten nitrid es can be obtained at 250 degrees C without hydrogen in the plasma. Th e surface is examined by atomic force microscopy (AFM) in order to eva luate growth conditions on silicon (100) substrate. Elastic recoil det ection analysis indicates that the hydrogen content is about 16% at th e surface and 10% at the silicon-film interface. XRD analysis show a t ungsten or tungsten nitride crystallographic form for the films analyz ed. (C) 1998 Elsevier Science B.V.