A method for integrating a metal-containing film in a semiconductor device, for example a gate stack. In one embodiment, the method includes providing a substrate in a process chamber, depositing the tungsten-containing film on the substrate at a first substrate temperature by exposing the substrate to a deposition gas containing a tungsten carbonyl precursor, heat treating the tungsten-containing film at a second substrate temperature greater than the first substrate temperature to remove carbon monoxide gas from the tungsten-containing film, and forming a barrier layer on the heat treated tungsten-containing film. Examples of tungsten-containing films include W, WN, WSi, and WC. Additional embodiments include depositing metal-containing films containing Ni, Mo, Co, Rh, Re, Cr, or Ru from the corresponding metal carbonyl precursors.