Hard x-ray photoelectron spectroscopy study of As and Ga out-diffusion in In 0.53Ga 0.47As/Al 2O 3 film systems

Abstract

Hard x-ray photoelectron spectroscopy (HAXPES) was performed on In 0.53Ga 0.47As/Al 2O 3 gate stacks as deposited and annealed at 400°C, 500°C, and 700°C to test for out-diffusion of substrate elements. Ga and As core-level intensities increase with increasing anneal temperature, while the In intensity decreases. HAXPES was performed at two different beam energies to vary the surface sensitivity; results demonstrate Ga and As out-diffuse into the Al 2O 3 film. Analysis suggests the presence of an interlayer containing Ga and As oxides, which thickens with increasing anneal temperature. Further diffusion, especially of Ga, into the Al 2O 3 film is also observed with increasing anneal temperature. © 2012 U.S. Government.