Methods for depositing a molybdenum nitride film on a surface of a substrate are disclosed. The methods may include: providing a substrate into a reaction chamber; and depositing a molybdenum nitride film directly on the surface of the substrate by performing one or more unit deposition cycles of cyclical deposition process, wherein a unit deposition cycle may include, contacting the substrate with a first vapor phase reactant comprising a molybdenum halide precursor, and contacting the substrate with a second vapor phase reactant comprising a nitrogen precursor. Semiconductor device structures including a molybdenum nitride film are also disclosed.