ELECTRICAL CHARACTERIZATION OF ANODICALLY GROWN NATIVE-OXIDE ON GAINSB

Surface passivation of single crystal bulk grown Ga1-xInxSb with x = 0 .08-0.18 is investigated using anodically grown native oxide and MOS d evices. Electrical characterization pf the interface is performed by u sing capacitance-voltage and conductance-voltage measurements at room temperature. The as-grown film shows relatively large hysteresis and h igh densities of negative (positive) fixed interface charges at the n- (p-) type interface. A long-time low-temperature annealing significan tly improves interface properties, while a high temperature annealing degrades the interface. Very good interface properties are obtained fo r n-type wafers, with a fixed interface charge density of around mid 1 0(10) cm(-2) (either positive or negative), an interface trap density in the range ai low 10(11) to less than 1 x 10(10) cm(-2) eV(-1) and a small hysteresis induced by slow trap effect. In contrast, the p-type interface is always characterized by a high density of interface trap s which leads to low-frequency-type C-V curves even at 1 MHz. (C) 1998 Elsevier Science Ltd. All rights reserved.