OXIDATION OF GAAS USING HELICON-WAVE EXCITED NITROGEN-OXYGEN-ARGON PLASMA

GaAs (100) substrates were exposed to the helicon-wave excited N-2-O-2 -Ar plasma without and with substrate heating at 200 degrees C. The ox ide dominantly composed of Ga2O3 and As2O3, was grown on the GaAs subs trate using this technique. The chemical composition of this oxide was highly uniform along the thickness of the oxide film. Relatively good capacitance-voltage (C-V) characteristics were obtained. X-ray photoe lectron spectroscopic data indicated that gallium nitride (GaN) bonds were formed at the oxide/GaAs interface only with both substrate heati ng and post-thermal annealing at 200 degrees C for 30 min in a nitroge n ambient. The formation of the GaN/GaAs interface improved the C-V ch aracteristics to some extent.