Behavior of electrically active point defects in irradiated MOCVD n-GaN

Formation and annealing of radiation-induced defects in doped and nominally undoped n-GaN are investigated by means of electrical measurements and Ram an spectroscopy. The production rate of defects turned out to be dependent on the dopant concentration. This suggests that at least one kind of native defects is involved in impurity-defect interactions at room temperature. T wo prominent stages of defect annealing are revealed. The annealing process es at T greater than or equal to 100 degrees C are associated with mobile n ative defects. A considerable fraction of radiation defects is still presen t in the materials after annealing to T greater than or equal to 750 degree s C. (C) 1999 Elsevier Science B.V. All rights reserved.