The effect of Mg doping on stacking fault formation in c-plane GaN grown by metal-organic chemical-vapour deposition was studied for Mg concentration between 2 x 1018 and 5 x 1019/cm3. Transmission electron microscopy studies demonstrated a direct correlation between the increasing Mg content and the number of small (3 to 10nm long) stacking faults present. The energy dispersive X-ray analysis line profile of a stacking fault showed that the Mg-impurity atom resides at a distance approximately 5nm from the stacking fault. Cathodoluminescence mapping revealed that the Mg-doped regions radiated at energies corresponding to known stacking fault emission peaks. Stacking fault related peaks in cathodoluminescence spectra showed metastability, which might be attributed to transfer processes involving Mg acceptors and nearby associated stacking faults.

Luminescence Related to High Density of Mg-Induced Stacking Faults in Homoepitaxially Grown GaN. S.Khromov, C.G.Hemmingsson, H.Amano, B.Monemar, L.Hultman, G.Pozina: Physical Review B, 2011, 84[7], 075324