Photo-Activated Synthesis of Functional Oxide Thin Films

摘要

We report on the effect of ultra-violet (UV) irradiation on structural and interfacial phenomena in thin film pure and doped zirconia grown by physical vapor deposition. Interfacial layer formation by substrate oxidation and resultant densification of zirconia layer was found in yttria doped zirconia (YDZ) films grown on Si, while no change was observed in identical films grown on Ge. A comparison of un-doped zirconia and YDZ films indicates yttria doping significantly assists the structural changes during UV irradiation. Interestingly, the effect of UV photons becomes minimal at approximately 300 oC in films grown on Si, while the effect of UV becomes more pronounced in YDZ films grown on Ge. An interfacial layer was formed between YDZ and Ge substrate at 300 oC in presence of UV irradiation, in contrast to the sharp interface maintained even after annealing at 300 oC without UV. Those results suggest that photon irradiation may be an elegant approach to tailor structural and interfacial properties at near-atomic length scales.