In one embodiment, a method for forming a tungsten barrier material on a
substrate is provided which includes depositing a tungsten layer on a
substrate during a vapor deposition process and exposing the substrate
sequentially to a tungsten precursor and a nitrogen precursor to form a
tungsten nitride layer on the tungsten layer. Some examples provide that
the tungsten layer may be deposited by sequentially exposing the
substrate to the tungsten precursor and a reducing gas (e.g., diborane or
silane) during an atomic layer deposition process. The tungsten layer may
have a thickness of about 50 .ANG. or less and tungsten nitride layer may
have an electrical resistivity of about 380 .mu..OMEGA.-cm or less. Other
examples provide that a tungsten bulk layer may be deposited on the
tungsten nitride layer by a chemical vapor deposition process.