Photo-electrochemical wet etching in KOH solutions and subsequent scanning electron microscopy was applied to investigate the defect structure in epitaxially lateral overgrown GaN. A cross-sectional photo-electrochemical wet-etching technique was developed in order to reveal easily the threading dislocations at a spatial resolution of about 20nm. There was a rich defect structure in the laterally overgrown regions.

Revealing the Defect Structure in Laterally Overgrown GaN Stripes Utilizing Photoelectrochemical Etching Techniques. T.Riedl, F.Hitzel, A.Hangleiter, S.Miller, A.Weimar, G.Brüderl, A.Lell, V.Härle: Japanese Journal of Applied Physics-1, 2003, 42[6A], 3381-2