Electrophysical properties of anode oxide films on an indium antimonide surface

Abstract

Anode oxide films are widely used for the passivation of the surface of semiconductors of group AIIIBV (GaAs [1–5], InSb [6–8], InAs [9], etc.) and as a subgate dielectric in MOS devices on a base of these materials. As well as a study of the properties of the boundary of separation of an anode oxide-semiconductor, the investigation of the electrophysical properties of such anode oxide films is an independent and extremely important problem. This is due to the fact that such characteristics of MOS devices as the charge stability, hysteresis phenomena, leakage currents through the gate, etc., are largely determined by the volume properties of the dielectric layer (by the spectrum of localized electron states in the volume, the mechanism of charge transfer through the dielectric film, etc.). At the same time, much less attention has been paid to the study of the properties of anode oxide films than to the investigations of the boundary of separation of a dielectric and a semiconductor. In this paper we investigate the electrophysical properties of anode oxide films of indium antimonide obtained by anode oxidation of a semiconductor substrate in a 0.1 N aqueous solution of KOH. We measured the dependence of the capacitance of the anode oxide on frequency (f), on temperature (T), and on the bias voltage (V), as well as the DC current-voltage characteristics.