Photoluminescence characterization of Mg implanted GaN

Single crystalline (000l) gallium nitride layers, capped with a thin epitax ial aluminum nitride Laver, were implanted with magnesium and subsequently annealed in vacuum to 1150-1300 degreesC for 10-60 minutes. Photoluminescen ce (PL) measurements showed the typical donor acceptor pair (DAP) transitio n at 3.25 eV after annealing at high temperatures, which is related to opti cally active Mg accepters in GaN. After annealing at 1300 degreesC a high d egree of optical activation of the implanted Mg atoms was reached in the ca se of low implantation doses. Electrical measurements, performed after remo ving the AlN-cap and the deposition of Pd/Au contacts, showed no p-type beh avior of the GaN samples due to the compensation of the Mg accepters with n ative n-type defects.