A method for forming a tungsten layer on a substrate surface is provided. In one aspect, the method includes positioning the substrate surface in a processing chamber and exposing the substrate surface to a soak. A nucleation layer is then deposited on the substrate surface in the same processing chamber by alternately pulsing a tungsten-containing compound and a reducing gas selected from a group consisting of silane, disilane, dichlorosilane and derivatives thereof. A tungsten bulk layer may then be deposited on the nucleation layer using cyclical deposition, chemical vapor deposition, or physical vapor deposition techniques.