Facile preparation of sol–gel-derived ultrathin and high-dielectric zirconia films for capacitor devices

This study successfully prepared zirconia ultrathin films from the sol–gel solution with dispersion of zirconium halide in 1-octanol solvent. The film was subjected to annealing treatments after sol–gel spin-coating, and the films of interest were evaluated. The amorphous morphology of the zirconia film was identified using high-resolution transmission electron microscopy and X-ray diffractometry. The plot of the current density with respect to the electric field demonstrates that the as-deposited film at 500 °C annealing exhibited an inferior leakage current, whereas 600 °C annealing stabilized the film with a satisfactory leakage current of 10−8 to 10–9 A/cm2. The out-gassing behavior of the sol–gel-derived thin film was evaluated using a thermal desorption system, that is, atmospheric pressure ionization mass spectrometry. The dielectric constant of the film was dependent on the retention effect of the preparation solvents. The low residual solvent for the preparation of the thin film with 1-octanol solvent and 600 °C annealing contributed to the superior high-k property.