Infrared and Raman Spectroscopic Studies of Optically Transparent Zirconia (ZrO2) Films Deposited by Plasma-Assisted Reactive Pulsed Laser Deposition

Plasma-assisted pulsed laser deposited zirconia (ZrO2) films were studied by Fourier transform infrared (FT-IR) and Raman spectroscopy for structural characterization and thermal stability in combination with optical characterization by spectroscopic ellipsometry and optical transmission measurements. Only the monoclinic ZrO2 phase was positively identified from the infrared and Raman spectra of the as-deposited ZrO2 films, which show excellent optical transparency from the ultraviolet to the near infrared as revealed by optical characterization. The as-deposited ZrO2 films are free of any SiOx interfacial layer when deposited on silicon. The prepared ZrO2 films exhibit good thermal stability in their structural, optical, and interfacial properties up to 900 degrees C. Upon annealing above 1100 degrees C, a silicon oxide interfacial layer forms due to the oxidation of the silicon substrate surface by the oxygen diffused from the oxide film to the silicon substrate at high temperatures.