Effects of selenious acid treatment on GaAs Schottky contacts

摘要

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