Al2O3/NbAlO/Al2O3 sandwich gate dielectric film on InP

Al2O3/NbAlO/Al2O3 sandwich dielectric films were grown on InP substrate and annealed. X-ray reflectivity measurements suggested that 1.0 nm interfacial layer existed at InP interface, x-ray diffraction and high resolution transmission electron microscopy indicated the films were crystallized. X-ray photoelectron spectra indicated the oxidization of InP substrate, and the valence-band offset between the dielectric film and InP interface was calculated to be 3.1 eV. The electrical measurements indicated that the leakage current density was 40 mA/cm(2) at gate bias of 1 V, and the equivalent oxide thickness and the dielectric constant were 1.7 and 20 nm, respectively.