The growth of Ni3Si surface films on Ni-12.7at%Si alloys has been measured during lMeV electron irradiation. Stereoscopic techniques were used to determine film thickness from dark field images formed from Ni3Si superlattice reflections. Parabolic growth kinetics are observed at lower temperatures. However, at higher temperatures, deviations from parabolic kinetics are observed after short irradiation times. Such deviations have not been observed in bulk specimens during bombardment with energetic ions and, therefore, may be due to foil thickness effects.