Effects of selenious acid treatment on GaAs Schottky contacts

The influence of selenious acid treatment on the GaAs surface and the M-GaA s interface electronic properties was studied. It is shown by XPS (x-ray ph otoelectron spectroscopy) analysis that such treatment deoxidizes the GaAs surface and forms a thin layer (< 3.0 nm) of selenium-gallium-arsenide comp ounds. Reduction of the Al-GaAs Schottky barrier effective height and low f requency noise was observed. The Schottky barrier height dependency on the metal work function is stronger for selenious-acid-treated GaAs surfaces th an for conventionally cleaned ones, however far from the Schottky limit. Th is discrepancy is attributed to the intensity and type of interface reactio ns during Schottky contact formation on Se-treated surfaces.