THE EFFECTS OF POINT-DEFECTS ON THE ELECTRICAL ACTIVATION OF SI-IMPLANTED GAAS DURING RAPID THERMAL ANNEALING

The effects of point defects on the electrical activation of Si-implanted GaAs during rapid thermal annealing were investigated using slow positron beam, cross-sectional transmission electron microscopy, and Hall measurements. The increase of the Ga vacancy concentration in the GaAs substrate induced by the SiO2 cap layer on the substrate during annealing is observed to decrease the activation efficiency and the number of extrinsic stacking faults via the recombination of interstitials with vacancies. It is found that the efficiency of the carrier creation is not dependent upon the Ga vacancy concentration during the rapid thermal annealing of Si-implanted GaAs. Hence, it is proposed that the electrical activation of Si-implanted GaAs is not due to the implantation-induced vacancies but to the self-exchange of interstitial Si atoms with the host Ga substitutional atoms.