An X-ray and TEM study of inhomogeneous ordering in AlxGa1−xN layers grown by MOCVD Original Research Article

Ordering along the c-axis has been observed both by high resolution X-ray diffraction and transmission electron microscopy in AlxGa1−xN grown by low pressure metal-organic vapor phase epitaxy on sapphire (0001). Beside the disordered alloy, AlGaN2 (1:1), and Al0.25Ga0.75N (3:1), there is an additional type with a quite large unit cell. In the latter, the c parameter is six times larger than that of the disordered alloy.