A method for selectively depositing an amorphous silicon film on a substrate comprising a metallic nitride surface and a metallic oxide surface is disclosed. The method may include; providing a substrate within a reaction chamber, heating the substrate to a deposition temperature, contacting the substrate with silicon iodide precursor, and selectively depositing the amorphous silicon film on the metallic nitride surface relative to the metallic oxide surface. Semiconductor device structures including an amorphous silicon film deposited by selective deposition methods are also disclosed.