A high-resolution X-ray diffraction study was made of the microstructure and dislocations in InN films grown onto sapphire (00•1) using metalorganic chemical vapor 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. Extrapolating from these results, molecular beam epitaxialy-grown InN film exhibited an edge-type dislocation density of 4.0 x 109/cm2, which was about 10 times higher than the density of screw-type dislocations. In metalorganic chemical vapor deposition-grown InN samples, the edge-type dislocation density was as high as 2.1 x 1010/cm2, and the screw-type dislocation density was 1.3 x 109/cm2. This indicated that the edge was the predominant dislocation type in InN films. By comparing the reported transmission electron microscopy results, the accuracy of evaluation for the 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