Application of high-resolution X-ray diffractornetry to the structural study of epitaxial multilayers on novel index surfaces

Abstract The applicability of high-resolution X-ray diffractometry (HRXRD) to the structural characterization of epitaxial structures on arbitrarily oriented surfaces is shown. This technique was used to study piezoelectric InGaAs/GaAs multiquantum well and superlattice p-i-n photodiodes grown on (001) and (111)B GaAs. The structural information obtained by HRXRD was important for understanding the optoelectronic behaviour of the diodes, since the strain-induced piezoelectric field strongly affected their characteristics. The interpretation of the HRXRD experiments was possible thanks to a simulation model developed in our laboratory which allows the calculation of any symmetric or asymmetric reflection on an arbitrarily oriented substrate. We also show some examples of the asymmetric distortion of the strained unit cells owning to the substrate misorientation.