Morphology of non-polar (11•0) a-plane GaN epilayers on r-plane (1¯1•2) sapphire substrate grown by low-pressure metal-organic vapour deposition was investigated after KOH solution etching. Many micron- and nano-meter columns on the a-plane GaN surface were observed by scanning electron microscopy. An etching mechanism model was proposed to interpret the origin of the peculiar etching morphology. The basal stacking fault in the a-plane GaN played a very important role in the etching process.

The Etching of a-Plane GaN Epilayers Grown by Metal-Organic Chemical Vapour Deposition. S.R.Xu, Y.Hao, J.C.Zhang, X.W.Zhou, Y.R.Cao, X.X.Ou, W.Mao, D.C.Du, H.Hao: Chinese Physics B, 2010, 19[10], 107204