Cubic epilayers were investigated by using conventional X-ray pole figure and grazing incident diffraction pole figure methods. It was found that the hexagonal inclusions and cubic twins could be classified into 2 groups. One group was formed which had strictly crystalline orientations, while the other had crystalline misorientations. The former could be measured by means of conventional pole figures, and this revealed that the density of lamellar hexagonal grains and cubic twins on (111)Ga and (¯1¯11)Ga, along the [1¯10] direction, were higher than those on (¯111)N and (1¯11)N, along the [110] direction.

Polarity Dependence of Hexagonal Inclusions and Cubic Twins in GaN/GaAs(001) Epilayers Measured by Conventional X-Ray Pole Figure and Grazing Incident Diffraction Pole Figure. B.Qu, X.H.Zheng, Y.T.Wang, S.M.Lin, H.Yang, J.W.Liang: Journal of Crystal Growth, 2001, 226[1], 57-61