The interpretation of ohmic behavior in semi-insulating gallium arsenide systems

Abstract

The paper is concerned with the interpretation of measurements on semi-insulating gallium arsenide and, in particular, with the evaluation of effective bulk resistivities from the results of observations on two-electrode systems. These observations tend to be dominated by injection effects, even when the contacts used are nominally of low resistance. Order-of-magnitude errors can arise from this cause, even though the specimen may appear to exhibit ohmic behavior. Carrier concentration, field- and space-charge contours are calculated on the basis of a model within the realm of a small-signal theory, for conditions which correspond to lifetime, relaxation, and hybrid operating regimes.