N-type implantation doping of GaN

Doping characteristics of N/Si and N/Ge co-implanted GaN have been systematically investigated. N-type regions were produced in undoped GaN films by the co-implantation and subsequent annealing with an SiO2 encapsulation layer at high temperatures. The annealing procedures above 1100 and 1200degreesC were required to achieve an n-type activation for N/Si and N/Ge co-implanted GaN, respectively. The both samples show effective activation efficiencies of similar to50% after annealing at 1300degreesC. However, actual Si activation seems to be much higher than the Ge activation due to the different behaviors of implantation-induced damage. (C) 2003 Elsevier Ltd. All rights reserved.