The morphology of non-polar (11•0) a-plane GaN epilayers on r-plane (1¯1•2) sapphire substrates grown via 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 in order 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