ABSTRACT
It was found that GaAs was etched with a smooth surface by radical or atomic hydrogen. The etching rate was as high as 15 um/h at the substrate temperature of 850°C and tungsten(W)-filament temperature of 2000°C. Several experimental results indicate that this high etching rate is due to evaporation of Ga as gallium hydride. Reaction between atomic hydrogen and AlGaAs was different from that for GaAs. Aluminum could not be removed so easily as Ga, and an aluminum oxide layer is left on the AlGaAs surface.
