Oxidation induced AlAs/GaAs superlattice disordering

Rapid interdiffusion occurs at thin-film SiGe/GaAs interfaces when samples are annealed in oxygen containing ambients. Secondary ion mass spectroscopy and AlAs/GaAs superlattice disordering indicate that Ge and/or Si diffuse to depths of 200 nm after oxidation at 800°C for 30 min. Negligible diffusion is detected for anneals in forming gas. Dissociation, out-diffusion, and oxidation of the GaAs substrate at the surface are associated with the phenomenon.