Characteristics of LaAlO3/Si(100) deposited under various oxygen pressures

Abstract

High-k dielectric ${\mathrm{LaAlO}}_{\mathrm{3}}$ (LAO) thin films were deposited by laser molecular-beam epitaxy under various oxygen pressures. X-ray diffraction showed that the LAO films were amorphous. The chemical compositions and thickness of the LAO thin films were measured using Rutherford backscattering spectrometry. Al/LAO/Si metal–oxide–semiconductor capacitor structures were fabricated and measured. The leakage current density versus voltage curves showed that the leakage current of the LAO thin films decreased by increasing the oxygen pressure of the preparation. Specifically, when prepared under the active oxygen (containing atom oxygen), the leakage current of the LAO sample was lower than that prepared under the general oxygen. All of the capacitance–voltage curves have a positive shift along the voltage axis and the flatband voltage decreased with increasing oxygen pressures during the LAO thin-film preparation.