Ion bombardment in surface passivation of GaAs

Abstract

The electrical properties of SI GaAs substrates after oxygen ion bombardment have been investigated in the temperature range of 150–373K. It was found that the oxygen ion bombardment of poor substrates stabilised their surface electrical properties in the sense of increase of the breakdown voltage. Because of leakage current which increased when the ion dose was increased only ion bombardment for the dose range from 1012 to 5×1012cm−2 may have a practical significance. However, the dose of ion bombardment of 1012cm−2 seems to be optimal. In this case the breakdown voltages were about 50V for a 20μm electrode separation (i.e. 25kV/cm) and leakage sheet current densities were from 3×10−9 to 5×10−8A/mm at the temperature range from 293 to 373K.