SCHOTTKY-BARRIER HEIGHT OF PHOSPHIDIZED INGAAS

The Schottky barrier height of phosphidized InGaAs has been studied. The surface of InGaAs (In 53%) lattice-matched to InP is treated with gentle phosphine plasma. Schottky junctions are then formed on phosphidized InGaAs by evaporating various metals such as Au, Cu, Ti and Ag. True barrier heights estimated from the Richardson plot are found to be significantly dependent on the metal work function. Phosphidization forms a thin phosphorus layer in addition to substitution of phosphorus for arsenic, resulting in formation of metal-insulator-semiconductor (MIS) Schottky junctions. An effective barrier height as high as 0.7 eV is attained for Au/InGaAs MIS Schottky junctions as measured from the room temperature current-voltage characteristic, while the true barrier height of 0.55 eV, which is close to the Schottky limit, is estimated from the Richardson plot.