Methods of forming a metal carbide film are provided. In some embodiments, methods for forming a metal carbide film in an atomic layer deposition (ALD) type process comprise alternately and sequentially contacting a substrate in a reaction space with vapor phase pulses of a metal compound and one or more plasma-excited species of a carbon-containing compound. In other embodiments, methods of forming a metal carbide film in a chemical vapor deposition (CVD) type process comprise simultaneously contacting a substrate in a reaction space with a metal compound and one or more plasma-excited species of a carbon-containing compound. The substrate is further exposed to a reducing agent. The reducing agent removes impurities, including halogen atoms and/or oxygen atoms.