Thermal annealing characteristics of Si and Mg-implanted GaN thin films

In this letter, we report the results of ion implantation of GaN using Si-28 and Mg-24 species. Structural and electrical characterizations of the GaN thin films after thermal annealing show that native defects in the GaN films dominate over implant doping effects. The formation energies of the annealing induced defects are estimated to range from 1.4 to 3.6 eV. A 40 keV 10(14) cm(-2) Mg implant results in the decrease of the free-carrier concentration by three orders of magnitude compared to unimplanted GaN up to an annealing temperature of 690 degrees C. Furthermore, we have observed the correlation between these annealing-induced defects to both improved optical and electrical properties. (C) 1995 American Institute of Physics.