A reassessment of Te-doped GaAs

A reassessment of the structure of the impurity atmospheres at dislocations in GaAs highly doped with Te is proposed on the basis of new results obtained by DSL etching, EBIC, microRaman and TEM. The formation of etch depressions around dislocations suggests that an enhanced formation of the TeAsVGa acceptor complex has locally occurred, driven by the gettering of Te by the dislocations. This causes an undersaturation of Ga vacancies which favours the generation of extrinsic Frank loops around the dislocations and promotes dislocation climb.