Effect of implantation-parameters on the structural properties of Mg-ion implanted GaN

GaN is implanted with 90 keV Mg-ions and afterwards annealed at 1150°C in a rapid thermal annealing furnace. In order to study the dependence of damage generation during implantation on the different implantation parameters, the dose is varied between 1×1014 and 5×1015 Mg+ cm−2, the substrate temperature during implantation is varied from 25 to 550°C and the ion current density is varied between 0.5 and 20 μA cm−2. The defect concentration is examined by Rutherford backscattering spectroscopy/channeling. Up to doses of 2.5×1015 Mg+ cm−2, the implantation-damage can readily be reduced by annealing. Variation of the ion current density has no influence on defect generation. Implantation at higher temperatures shows an unusual behaviour as it results in an increase in damage