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 asdeposited ZrO ₂ films, which show excellent optical transparency from the ultraviolet to thenear 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 °C. Upon annealing above 1100 °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.