In one embodiment, a method for forming a tungsten material on a substrate
surface is provide which includes positioning a substrate within a
deposition chamber, heating the substrate to a deposition temperature,
and exposing the substrate sequentially to a first reducing gas and a
tungsten precursor gas to form a tungsten nucleation layer on the
substrate during an atomic layer deposition (ALD) process. The method may
further provide exposing the substrate to a deposition gas comprising a
second reducing gas and the tungsten precursor gas to form a tungsten
bulk layer on the tungsten nucleation layer during a chemical vapor
deposition (CVD) process. Examples include that the ALD and CVD processes
are conducted in the same deposition chamber or in different deposition
chambers.