Lattice location and thermal annealing behaviour studies of GaAs single crystals implanted with Co-atoms

Co-atoms have been implanted into n-type GaAs single crystals up to a dose of 2 x 1015 atoms/cm2. Moessbauer Spectroscopy was used together with Proton Induced X-ray Excitation and Rutherford Backscattering Spectrometry in Channeling geometry to study the recovery of the GaAs-crystal from the implantation damage and the final lattice locations of the Co-atoms. Epitaxial regrowth of the GaAs was found to take place in the annealing temperature region from 3000C - 4500C. At 9000C rapid thermal annealing an epitaxial Co-phase was found at the surface with the Co-atoms partially blocking the GaAs<110> channel. (Auth.)