Barrier height enhancement of Au Schottky junctions on phosphine-plasma treated n-AlInAs

Abstract

The effect of surface phosphidisation on the barrier height of Au/AlInAs (Al 48%) Schottky diodes was studied. The surface of AlInAs is treated with phosphine (PH/sub 3/) plasma at 250 degrees C. Schottky junctions formed on the phosphidised AlInAs employ a metal insulator-semiconductor (MIS) structure due to the existence of phosphorus related layers deposited on the AlInAs surface. An effective barrier height as high as O.82eV was successfully obtained for the Au/n-AlInAs Schottky junction with a true barrier height of 0.74eV which is close to the ideal barrier height expected for the Schottky-Mott model. Owing to the enhanced barrier height, the reverse leakage current can be reduced by more than four orders of magnitude in comparison with that of conventional diodes.