A high-resolution X-ray diffraction study was made of microstructure and dislocations in InN films, grown onto sapphire (00•1) by metalorganic chemical vapour deposition and molecular beam epitaxy. The mosaic tilt, twist, and correlation lengths of InN films were determined by using symmetrical and asymmetrical reflections as well as reciprocal space mapping. It was deduced from these results that molecular beam epitaxially-grown InN films contained edge dislocations with a density of 4.0 x 109/cm2; which was about 10 times higher than the density of screw dislocations. In metal organic chemical vapour deposition-grown InN sample, the edge dislocation density was as high as 2.1 x 1010/cm2, and the screw dislocation density was 1.3 x 109/cm2. By comparison with these transmission electron microscopy results, the accuracy of evaluation of dislocation density using the mosaic model was proved.

Microstructure and Dislocation of Epitaxial InN Films Revealed by High Resolution X-ray Diffraction. B.Liu, R.Zhang, Z.L.Xie, H.Lu, Q.J.Liu, Z.Zhang, Y.Li, X.Q.Xiu, P.Chen, P.Han, S.L.Gu, Y.Shi, Y.D.Zheng, W.J.Schaff: Journal of Applied Physics, 2008, 103[2], 023504