The influence of Mg doping upon structural defects in Al0.13Ga0.87N layers, grown onto sapphire substrates by metalorganic chemical vapor deposition, was studied by using transmission electron microscopy. Upon increasing the Mg-source flow rate, a reduction in dislocation density occurred up to a Mg-source flow-rate of 0.103µmol/min. Whereas vertical-type inversion domain boundaries were observed in Al0.13Ga0.87N layers grown using a low Mg-source flow-rate, the inversion domain boundaries in Al0.13Ga0.87N layers grown using a high Mg-source flow-rate had horizontally multi-faceted shapes. A change in polarity of the inversion domain boundaries of horizontal type also resulted in a 180° rotation of pyramidal defects within the same AlGaN layer.

Influence of Mg Doping on Structural Defects in AlGaN Layers Grown by Metalorganic Chemical Vapor Deposition. H.K.Cho, J.Y.Lee, S.R.Jeon, G.M.Yang: Applied Physics Letters, 2001, 79[23], 3788-90