DISCRIMINATION OF DEFECTS AT E//c minus 0. 81 eV OF GaAs USING HIGH ELECTRIC FIELD EFFECTS.

The midgap defect in different GaAs materials is often ambiguously denoted as EL-2. In this work the conventional DLTS method is applied to study the defect energy level and defect spatial concentration distribution for various materials, and the RDLTS method is used to measure the enhanced emission rate at high electric field. The samples used are as grown horizontal Bridgman with and without a high temperature anneal, and Cr-doped liquid encapsulated Czochralski grown material. Oxygen implanted HB with anneal and liquid phase epitaxial films with and without anneal are also used. The results indicate that the carrier emission kinetic at high electric field for the Cr-doped LEC sample is different from others. The RDLTS technique is shown to be able to discriminate the defects observed in different materials.