Simulation of X-Ray Diffraction Spectra for AlN/GaN Multiple Quantum Well Structures on AlN(0001) with Interface Roughness and Variation of Vertical Layers Thickness
O. I. Liubchenko, V. P. Kladko
V. E. Lashkaryov Institute of Semiconductor Physics, NAS of Ukraine, 41 Nauky Ave., UA-03028 Kyiv, Ukraine
Received: 06.04.2018. Download: PDF
A detailed XRD analysis of AlN/GaN multiple quantum well (MQW) structures grown on AlN(0001) substrates is proposed. The effect of roughness on the 2$\theta‒\omega$ scans measured in Bragg diffraction for symmetrical reflections is investigated together with the effect of depth variation of the well and barrier thickness. As shown, the magnitude of depth variation of the well and barrier thickness results in an asymmetrical broadening of the satellite peaks of the 2$\theta‒\omega$ scans. Roughness causes their symmetrical expansion that allows separating the influence of both effects. Several reasons of asymmetrical broadening of satellite peaks are considered: variation of the thickness period, variation of the average lattice parameter inherent to the period, which depends on the thickness ratio of the layers in the period, and their combination. The efficiency of the described method is illustrated in detail by numerical simulations.
Key words: dynamical X-ray diffraction, multiple quantum well structure, thickness variation with depth, computer simulation, superlattice.
URL: http://mfint.imp.kiev.ua/en/abstract/v40/i06/0759.html
DOI: https://doi.org/10.15407/mfint.40.06.0759
PACS: 61.05.cc, 61.05.cp, 68.35.Ct, 68.65.Ac, 68.65.Cd, 68.65.Fg, 81.05.Ea
Citation: O. I. Liubchenko and V. P. Kladko, Simulation of X-Ray Diffraction Spectra for AlN/GaN Multiple Quantum Well Structures on AlN(0001) with Interface Roughness and Variation of Vertical Layers Thickness, Metallofiz. Noveishie Tekhnol., 40, No. 6: 759—776 (2018)