VACANCY COMPLEXES IN GAAS - EFFECTS ON IMPURITY COMPENSATION

The energetics of shallow impurity compensation in GaAs via reactions of the type VAs (VGa+GaAs), where V denotes a vacancy and GaAs a Ga-antisite defect is examined. It is proposed that in n-type GaAs this single-atom-displacement reaction is unstable with respect to a similar type of process, namely, 2VAs (VAs+VGa+GaAs). The latter does not lead to any compensation of donors, thereby removing discrepancies between theoretical predictions and experimental results on donor passivation by native defects in GaAs. © 1990 The American Physical Society.