In this work, a barrier height of ∼0.7 eV is constantly observed from theIn0.53Ga0.47AsSchottky diodes, regardless of the utilization of different metals as Schottky contacts. By the addition ofPr2O3andIn2O3in the liquid phase epitaxy, a very low background impurity concentration is also obtained. The low background concentration is credited to the gettering effect from the addition of Pr and oxygen in the growth melt. The high Schottky barrier is attributed to the formation of a stable oxide layer on the surface of the epilayer, which in turn forms a metal-insulator-semiconductor structure in our Schottky diodes. The high Schottky barrier is very stable even at a high measuring temperature and was repeatedly obtained after four months of exposure to the environment. ©1997 American Institute of Physics.