Redistribution of point defects during radiation defect annealing in GaAs

The processes of migration and redistribution of point defects, generated in GaAs as a result of irradiation and released during annealing of the main isolated radiation defects, were studied. It was found that some point defects, generated during irradiation, migrate at significant distances and deposit at neutral impurity inclusions. Interaction of these defects with shallow impurities results in activation of the latter, which leads to the formation of n+ charged defect clusters. The conclusion reached as a result of the experiments is that one of the types of isolated radiation defects, which determines the change in GaAs electrical properties at T = 300 K, is a complex consisting of intrinsic defects. It is shown in this paper, that the main fraction of the point defects, released as a result of thermal dissociation of the stated complexes at T = 500 K, annihilates at sinks, while the rest of them deposit at neutral inclusions with the formation of n+ charged defect clusters. It is noted that in GaAs as opposed to Si and Ge, an appreciable formation of new, more thermally stable types of isolated defects is not observed during thermal annealing of the main isolated radiation defects. (author)