Thermal evolution of Implantation Damages in Mg-Implanted GaN layers grown on Si

We report on the structural characterization of Mg-implanted and annealed GaN layer on Si (111). Anneals ranging from 400 degrees C to 1100 degrees C are performed on samples implanted with 10(13) - 10(15) at/cm(2) Mg doses. A comparative study of the evolution of the damage in these samples as a function of annealing temperatures and implanted doses is performed by using photoluminescence (PL) and X-Ray Diffraction (XRD). For low Mg dose, the induced strain, measured via XRD, can be relaxed at relatively low temperature, i.e. 500 degrees C, while a 1000 degrees C anneal is required for higher dose. PL characteristics bands of Mg implanted in GaN are evidenced. Comparison of XRD and PL results show that the strain correction and the increase of the PL signal are not simultaneous. The trend in the evolution of the PL bands indicates that a higher thermal treatment would allow a better optical activation of Mg.