Implantation and diffusion of As-73 in GaAs and GaP

Self-diffusion on the As sublattice in intrinsic GaAs and foreign-atom diff usion on the P sublattice in intrinsic GaP were investigated in a direct wa y by As tracer diffusion measurements using the radioisotope As-73. For thi s purpose As-73 was implanted in both materials at the ISOLDE facility of C ERN. Then diffusion annealings were performed followed by serial sectioning and counting of the radioactivity in each section. The resulting profiles were simulated within a computer model which accounts for the observed loss of tracer to the diffusion ambient. The so-obtained diffusion coefficients for As in GaAs and GaP are compared with existing diffusivities in these c ompounds.