The Influence of the Deposition and Annealing Temperatures on the Structure and Properties of Zirconium Oxide

ZrO2 thin films were deposited by atomic vapor deposition (AVD) using Zr[OC(CH3)3]4 as precursor. The maximum growth rate (~7 nm/min) and the strongest crystalline phase with preferential tetragonal/cubic orientation were obtained at 400{degree sign} C. Growth rate and crystallinity dropped down with increasing or decreasing deposition temperature. Additionally, the increase of the deposition temperature changed the crystalline ZrO2 phase from cubic/tetragonal to monoclinic. Annealing reduced the cubic/tetragonal phase and enhanced the monoclinic one. The values of the dielectric constant (up to 32) varied depending on the deposition temperature, film thickness, and annealing temperature. Leakage current density measurements showed typical values of about 2×10-7 Acm-2 at 1×106 Vcm-1. The midgap density of interface states was Dit = 5×1011 eV-1cm- 2. Due to annealing the leakage current density and the density of interface states were lowered to 10-7 A/cm-2 and to 1010 eV-1cm-2, respectively. However, the dielectric constant also decreased.