LATERAL OXIDATION OF BURIED ALXGA1-XAS LAYERS IN A WET AMBIENT

The lateral oxidation of buried AlxGa1-xAs layers with high Al content (x = 0.8-1) is investigated, using an oxidation process in a wet N-2H2O ambient at 370-450 degrees C. The oxidation is clearly selective a nd significantly affected by process temperature, material composition , AlxGa1-xAs layer thickness, and the geometry of the oxidized structu res. An asymptotic oxide growth with constant activation energies for the reactive process and for the transport mechanism is observed. The experimental oxidation behavior coincides well with a model of self-bl ocking pores. (C) 1997 American Institute of Physics.