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 (La2O3) thin films were grown on Si(100) by atomic layer deposition technique using lanthanum 2,2,6,6-tetramethyl-3,5-heptanedione and water (H2O) 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 La2O3 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/cm2 at the bias voltage of + 1 V. It was also observed that the capacitance increased and the shift of the flat band voltage, VFB, disappeared with the post-annealing.