Electrical properties of La2O3 thin films grown on TiN/Si substrates via atomic layer deposition

The electrical as well as the structural properties of La2O3 thin films on TiN substrates were investigated. Amorphous stoichiometric La2O3 thin films were grown at 300 °C via atomic layer deposition technique by using lanthanum 2,2,6,6-tetramethyl-3,5-heptanedione [La(TMHD)3] and H2O as precursors. Post-annealing of the grown film induced dramatic changes in structural and the electrical properties. Crystalline phases of the La2O3 film emerged with the increase of the post-annealing temperature. Metal-insulator-metal (MIM) capacitor was fabricated to measure the electrical properties of the grown film. The dielectric constant of the La2O3 thin films increased with annealing temperature to reach the value of 17.3 at 500 °C. The leakage current density of the film post-annealed at 400 °C was estimated to be 2.78 × 10−10 and 2.1 × 10−8 A/cm2 at ±1 V, respectively.