Abstract: A method of controlling the resistivity and morphology of a tungsten film is provided, comprising depositing a first film of a bulk tungsten layer on a substrate during a first deposition stage by (i) introducing a continuous flow of a reducing gas and a pulsed flow of a tungsten-containing compound to a process chamber to deposit tungsten on a surface of the substrate, (ii) flowing the reducing gas without flowing the tungsten-containing compound into the chamber to purge the chamber, and repeating steps (i) through (ii) until the first film fills vias in the substrate surface, increasing the pressure in the process chamber, and during a second deposition stage after the first deposition stage, depositing a second film of the bulk tungsten layer by providing a flow of reducing gas and tungsten-containing compound to the process chamber until a second desired thickness is deposited.