Strain profiling of AlInN/GaN distributed Bragg reflectors using in situ curvature measurements and ex situ X-ray diffraction

Abstract

In this work, we show the use of in situ curvature and X-ray measurements to evaluate the metal organic vapor phase growth process of distributed Bragg reflectors consisting of an AlInN/GaN system. At first, it is investigated how the initial wafer bow and the heating of the bare substrates influences the curvature measurements. The strain induced by thermal mismatch and lattice mismatch is discussed at the example of multilayer AlInN/GaN Bragg mirror structures on sapphire substrate. We will demonstrate that thereby an estimation of the composition in the AlInN layers is possible. Additionally the samples were examined with multiple X-ray diffraction techniques, as symmetrical and asymmetrical reciprocal space maps, grazing-incidence in-plane diffraction and X-ray reflectivity. These results are compared with the in situ measurements.