NEW TECHNIQUE TO DOPE GAAS CRYSTALS WITH THE IN-111 ]CD-111 PROBE FOR PERTURBED-ANGULAR-CORRELATION SPECTROSCOPY

Perturbed-angular-correlation (PAC) spectroscopy is an important technique for measuring defect and dopant interactions in group IV and III-V semiconductors. The probe of choice for most of the successful PAC experiments on semiconductors has been In-111 --> Cd-111 introduced by ion implantation. To expand the gamut of PAC experiments that can be performed on III-V semiconductors, we have developed a simple closed-tube, vapor-phase-epitaxy (VPE) technique to produce In-111-doped GaAs single-crystal epitaxial materials. PAC measurements on these crystals yielded nearly nonperturbed correlations that indicate that the In-111 probe was incorporated substitutionally into the GaAs crystals. These correlations differ significantly from the previously reported weakly perturbed correlations that were measured on GaAs crystals implanted with In-111 ions. An exploratory experiment using this VPE technique also showed that Sn can be incorporated along with In-111.