Effect of Surface Phosphidization on GaAs Schottky Barrier Junctions

Phosphidization of GaAs surface has been attempted by exposing to the plasma of PH3 and H2 gases. The presence of P atoms near the GaAs surface is confirmed by secondary ion mass spectroscopy analysis. The barrier height of Schottky junctions formed on the phosphidized GaAs surface varies depending on metal work functions in contrast to the conventional case of a rather constant barrier height independent of metal species. The density of the surface state is estimated to be 1.3×1013 cm-2·eV-1 from the dependence of the barrier height on the metal work function.