Characterization of Ca and C implanted GaN

Ca+, Ar+ and C+ ions were implanted in molecular beam epitaxy (MBE) grown GaN. Results of Rutherford backscattering (RBS)/channeling measurements are in agreement with simulated distributions of the implanted ions and of the implantation induced damage. Doses higher than 1×1015 cm−2 result in the formation of heavy damage, which can be partially removed by rapid thermal annealing at 1150°C. After ion implantation followed by annealing, Hall- and Raman-measurements indicate a reduction of the carrier density due to damage caused by the irradiation. Photoluminescence (PL)-measurements show an increase in the intensity of donator-acceptor-pairs compared to the donator-bound exciton.