High-resolution X-ray diffraction study of AlAs/Al0.5Ga0.5As/GaAs quantum well structures grown by molecular beam epitaxy on (11 n)A GaAs

In order to experimentally try out a new generalized X-ray diffraction theo retical model [A. Sanz-Hervas et al., J, Appl. Phys. 82 (1997) 3297], we ha ve carried out a detailed analysis of high-resolution X-ray diffraction mea surements of AlAs/Al0.5Ga0.5As/GaAs single quantum well structures with a n ominal well width of 100 Angstrom grown side-by-side on (1 1 1)A, (1 1 2)A, (1 1 3)A, (1 1 4)A, (1 1 0) and (0 0 1) GaAs substrates by molecular beam epitaxy. For each substrate orientation we have measured various symmetric and asymmetric reflections at different azimuths which were fitted by diffr action curves obtained through the theoretical model that was being tested. The HRXRD study enabled us to study the crystal quality and the main struc tural parameters of the samples. We achieved an excellent agreement between the measurements and the simulated curves by using a single set of structu ral values for each substrate orientation. This proves the validity of our simulation model to analyze high-resolution X-ray diffraction measurements of epitaxial structures grown on (1 1 n) substrate orientations. (C) 2000 E lsevier Science B.V. All rights reserved.