Niobium Oxide Thin Films Grown by Atomic Layer Epitaxy

Nb2O5 thin films were grown by atomic layer epitaxy (ALE) in the temperature range of 150–350°C using Nb(OC2H5)5 and H2O as precursors. All the films grown on glass substrates were amorphous, as indicated by X-ray diffraction analysis. The films exhibited smooth surfaces as observed by scanning electron microscopy and uniform thickness profiles with less than 7% variation in the gas flow direction. The refractive index of the films increased with deposition temperature, stabilizing at 2.4 at temperatures higher than 230°C. Backscattering spectrometry analysis indicated that the films were stoichiometric Nb2O5.