The present disclosure relates to the deposition of dopant films, such as doped silicon oxide films, by atomic layer deposition processes. In some embodiments, a substrate in a reaction space is contacted with pulses of a silicon precursor and a dopant precursor, such that the silicon precursor and dopant precursor adsorb on the substrate surface. Oxygen plasma is used to convert the adsorbed silicon precursor and dopant precursor to doped silicon oxide.