Thin ZrO2 films have been grown on Si(100) and on glassy carbon substrates using a novel atomic oxygen source in a standard molecular beam epitaxy system. The oxygen source produces a Aux of hyperthermal oxygen atoms with an ion/atom-ratio much less than 0.001 through electron stimulated desorption from a Ag alloy surface at an operating pressure <10(-8) Torr. The films were grown at room temperature and analyzed using Rutherford backscattering spectroscopy, x-ray diffraction (XRD), x-ray photoelectron spectroscopy and transmission electron microscopy (TEM). The results show the successful growth of fully stoichiometric ZrO2 films on nonheated Si(100) and on amorphous glassy carbon substrates at a rate of 0.58 mu m/hr. The XRD and TEM investigations indicate the formation of a mixed amorphous/orthorhombic film structure. Based on the film growth rate, the O flux produced by the electron stimulated desorption atom source is estimated to be 8 x 10(14) atoms/cm(2)s. This flux value is consistent with other determinations using ion scattering spectroscopy and pyromellitic dianhydride-oxydianiline polyimide (Kapton (R)) erosion experiments.