The structural state of non-polar a-plane GaN layers grown by MOVPE onto rplane

sapphire was investigated using X-ray diffraction methods. Interplanar

spacings were measured in three directions and the corresponding strains were

determined. The crystalline perfection was studied by measurement of diffraction

peaks of θ- and θ-2θ-scanning in Bragg- and Laue-diffraction geometry. Their

FWHM was analyzed by Williamson-Hall plots. Anisotropy of the elastic strains

and the peak broadening was revealed. It was shown that a different broadening of

diffraction pattern in two in-plane directions was not caused by mosaicity and can

be explained by a specific distribution of dislocations.

X-Ray Diffraction Study of Strain and Defect Structure of Nonpolar a-Plane GaNLayers

Grown on r-Plane Sapphire. R.N.Kyutt, M.P.Shcheglov, V.V.Ratnikov,

A.E.Kalmykov: Physica Status Solidi A, 2009, 206[8], 1757-60