SCANNING DEEP-LEVEL TRANSIENT SPECTROSCOPY INVESTIGATIONS ON GALLIUM-ARSENIDE

The present state of the art of the application of the scanning deep-level transient spectroscopy (SDLTS) technique is reported. Special attention is given to the theoretical modelling of the signal generation process, yielding important information on the factors influencing the spatial resolution to be attained. The experimental possibilities of the dedicated SDLTS equipment available now are described. This system was used to investigate point defects generated by plastic deformation in GaAs p+-n junctions induced by diamond indentations made at room temperature. A cloud of point defects (hole traps at E(v) + 0.5 eV) up to a distance of approximately 20 mum from the indentations has been detected by SDLTS. Interestingly, the deformation-induced point defects are localized in regions outside the slip bands rather than within the slip bands of the deformation-induced dislocations. Annealing experiments seem to contradict their interpretation as the second charge state of the EL2 level.