SIMULTANEOUS OBSERVATION OF SUBTHRESHOLD AND ABOVE-THRESHOLD ELECTRON-IRRADIATION INDUCED DEFECTS IN GAAS

Sub- and above threshold defects were introduced in n-type OMVPE grown GaAs during 3 keV and 3 MeV electron irradiation, respectively. The electrical properties of these defects were determined by DLTS measurements in samples that contained subthreshold defects only, above threshold defects only, as well as samples contained both type of defects. A careful examination of the low temperature DLTS peaks revealed that although the sub- and above threshold defects have similar properties, they are nevertheless distinguishable from each other and are therefore not the same as has previously been speculated.