5 nm thick lanthanum oxide thin films grown on Si(100) by atomic layer deposition: The effect of post-annealing on the electrical properties

Amorphous stoichiometric lanthanum oxide (La 2O 3) thin films were grown on Si(100) by atomic layer deposition technique using lanthanum 2,2,6,6-tetramethyl-3,5-heptanedione and water (H 2O) as precursors. The structural and electrical properties were investigated by transmission electron microscope, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), current–voltage ( I– V) and capacitance–voltage ( C– V) measurements. In particular, the effects of thermal annealing on the La 2O 3 film properties such as crystallinity, I– V, and C– V characteristics were measured. Post-annealing at 700 °C improved the electrical properties to reduce the leakage current density up to 2 × 10 − 7 A/cm 2 at the bias voltage of + 1 V. It was also observed that the capacitance increased and the shift of the flat band voltage, V FB, disappeared with the post-annealing.