X-ray diffraction analysis of MOCVD grown GaN buffer layers on GaAs(001) substrates

摘要

In order to understand the growth feature of GaN on GaAs (001) substrates grown by metal organic chemical vapor deposition (MOCVD), the crystallinity of GaN buffer layers with different thicknesses was investigated by using double crystal X-ray diffraction (DCXRD) measurements. The XRD results showed that the buffer layers consist of predominantly hexagonal GaN (h-GaN) and its content increases with buffer layer thickness. The nominal GaN (111) reflections with % at 54.74° can be detected easily, while (002) reflections are rather weak. The integrated intensity of reflections from (111) planes is 4―6 times that of (002) reflections. Possible explanations are presented.