Radiation Effects in Strained-Layer Superlattice (SLS) Structures

摘要

The effects of gamma and neutron irradiation on GaP/GaAsP strained-layer superlattices (SLS's) have been studied and compared with results on similar non-SLS alloys. The carrier removal rate was significantly greater in the non-SLS samples for both types of radiation. Gamma irradiation resulted in layer-dependent removal rates which produced oscillations in the doping profile. Gamma-induced introduction rates of two prominent traps were the same in the various SLS samples, and in the non-SLS alloy. Thermal annealing was also similar in all the samples with the shallower (0.3 eV) trap recovering sharply in a stage at 175 degrees C. This was accompanied by a disappearance of the carrier removal oscillations at a somewhat higher annealing temperature. In contrast, the degree of recombination-enhanced annealing, and its variation with applied hydrostatic pressure, was strongly dependent on sample characteristics. This type of recovery was much stronger in the non-SLS samples, and was dependent on the layer thicknesses in the SLS samples. Hydrostatic pressure was found to enhance this process in the non-SLS samples, but had no significant effect on recombination-enhanced annealing in the SLS samples. (ERA citation 10:000957)