Suppression of m-plane and c-plane slip through Si and Mg doping in partially relaxed (202¯1) InGaN/GaN heterostructures

Abstract

Several series of (202¯1) oriented InGaN/GaN heterostructures were grown to examine the impact of Si and Mg doping on stress relaxation by misfit dislocation formation. Si doping greatly reduced m-plane slip misfit dislocation lines as observed in cathodoluminescence, as well as reducing relaxation from c-plane slip as measured using x-ray diffraction reciprocal space maps. However, samples with the same degree of relaxation still showed reduced m-plane slip for the highly Si doped case. Mg doping showed a similar effect while experiments with Si–Mg co-doping reversed the effect.