Characterization of Al2O3 thin films of GaAs substrate grown by atomic layer deposition

摘要

Al2O3 thin films are grown by atomic layer deposition on GaAs substrates at 300 degrees C. The structural properties of the Al2O3 thin film and the Al2O3/GaAs interface are characterized using x-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), and x-ray photoelectron spectroscopy (XPS). the XRD results show that the as-deposited Al2O3 film is amorphous. For 30 atomic layer deposition growth cycles, the thicknesses of the Al2O3 thin film and the interface layer from the HRTEM are 3.3 nm and 0.5 nm, respectively. XPS analyses reveal that the Al2O3/GaAs interface is almost free from Al2O3.