On the defect structures in Te-doped GaAs

The defect clusters at grown-in dislocations typical of heavily Te-doped GaAs have been studied by several techniques yielding structural and electrical information with high spatial resolution. A mechanism for the generation of extrinsic dislocation loops around grown-in dislocations is proposed based on the supersaturation of Ga interstitials. Such supersaturation is caused by the undersaturation of Ga vacancies associated with the formation of TeAsVGa accepters in the surroundings of the grown-in dislocations because of the gettering of Te by the dislocations.