Composition, surface morphology and electrical characteristics of Al 2O 3–TiO 2 nanolaminates and AlTiO films on silicon

Abstract

We propose and demonstrate Metal-Oxide-Semiconductor structures comprising Al 2O 3–TiO 2 nanolaminate and AlTiO films. Composition, structural and electrical characteristics were studied in detail and compared to TiO 2 thin film-based structures. All dielectric films were evaporated using an electron beam gun (EBG) system on unheated p-Si substrate without adding O 2. MOS structures were investigated in detail before and after annealing at up to 950 °C in O 2 and N 2 + O 2 environments. The nanolaminate films remain in an amorphous state after annealing at 950 °C. The smallest quantum mechanical corrected equivalent oxide thickness measured was ∼1.37 nm. A large reduction of the leakage current density to 1.8 × 10 − 8 A/cm 2 at an electric field of 2 MV/cm was achieved by the annealing process.