In this work we present the application of ion beam assisted deposition (IBAD) to the growth of beta-FeSi2. Iron disilicide films, about 120 nm thick, were obtained by the deposition of Fe onto (001)Si single crystal maintained at T = 600-degrees-C. During evaporation a low energy (120-650 eV) Ar+ ion beam bombarded the growing film. Scanning and transmission electron microscopies were used to characterize respectively the morphology and structure of the deposited layer. A reduction in both the surface roughness and grain size was observed in the IBAD films with respect to those grown by standard deposition techniques. Moreover, a remarkable enhancement of the epitaxy was found for one of the IBAD samples.