Hydrogen ion treatments of oxidized GaAs(100) and AlGaAs(100) surfaces: surface stoichiometry and electronic properties

Near-surface GaAsAlGaAs quantum wells, with and without a GaAs cap, have been used as effective probes of the electronic properties of oxidized GaAs surfaces and AlGaAs surfaces. We find that the variation of surface stoichiometry due to hydrogen ion treatments appears to be similar for both oxidized AlGaAs and GaAs surfaces, as examined by Auger electron spectroscopy. However, the composition of the oxide significantly affects both hydrogenation process and the efficacy of surface passivation.