XPS characterization of Al2O3/ZnO ultrathin films grown by atomic layer deposition

The near-surface compositional properties of double-layer Al2O3/ZnO ultrathin films, grown on the n-type GaAs substrate using the atomic layer deposition (ALD) technique, are analyzed by means of high-resolution x-ray photoelectron spectroscopy (XPS). This structure has been used as the dielectric or the passivation layer in microelectronic devices, such as metal-oxide-semiconductor (MOS) capacitors, field-effect transistors, and Schottky junctions. The XPS spectra of double-layer Al2O3/ZnO thin films were obtained using monochromatic Al kα monochromatic radiation at 1486.6 eV and included an overall survey scan, in addition to the high-resolution spectra of Zn 2p, Al 2p, O 1s, Ga 2p, and As 3d.