Effect of cylindrical geometry on the wet thermal oxidation of AlAs

We have investigated the wet thermal oxidation of AlAs in cylindrical geome try, a typical configuration for vertical-cavity surface-emitting lasers. T hrough both experiment and theoretical calculations, we demonstrate a signi ficantly different time dependence for circular mesas from what has been re ported in the literature both in studies of stripes and in a study of circu lar mesas. We attribute this different time dependence to the effect of geo metry on the oxidation. (C) 1998 American Institute of Physics. [S0021-8979 (98)06824-8].