ANALYSIS OF IR ABSORPTION MAPPING OF DEFECTS IN LIQUID-ENCAPSULATED CZOCHRALSKI GAAS

The mapping of EL2 defects and those that give rise to reverse contras t absorption images in semi-insulating GaAs have an inverse spatial co rrelation in terms of defect concentrations. EL2 defects are known to be associated with arsenic antisites; those that give rise to the reve rse contrast image have recently been shown to be arsenic vacancies. W e propose that the inverse correlation of these defects results from a simple mechanism involving a perturbation of the reverse Frenkel reac tion on the arsenic sublattice, resulting from the presence of disloca tions.