Embodiments of the present invention relate to approaches for forming RMG FinFET semiconductor devices using a low-resistivity metal (e.g., W) as an alternate gap fill metal. Specifically, the semiconductor will typically comprise a set (e.g., one or more) of dielectric stacks formed over a substrate to create one or more trenches/channels (e.g., short/narrow and/or long/wide trenches/channels). A work function layer (e.g., TiN) will be provided over the substrate (e.g., in and around the trenches). A low-resistivity metal gate layer (e.g., W) may then be deposited (e.g., via chemical vapor deposition) and polished (e.g., via chemical-mechanical polishing). Thereafter, the gate metal layer and the work function layer may be etched after the polishing to provide a trench having the etched gate metal layer over the etched work function layer along a bottom surface thereof.