MODELING IMPERFECTIONS OF EPITAXIAL HETEROSTRUCTURES BY MEANS OF X-RAY-DIFFRACTION ANALYSIS

Interface intermixing of highly strained heterostructures was investig ated using high-resolution double-crystal X-ray diffractometry combine d with computer simulations. A method of modelling imperfections in se miconductor heterostructures was introduced to extract information fro m simulated and measured data in a fast and objective manner. The key steps of this method are i) the sensitivity analysis of experimental d iffraction curves with respect to imperfections, and ii) the developme nt of objective error criteria. The applicability of this method is de monstrated using highly strained [(InAs/GaAs)(12)/InGaBs](9) superlatt ices grown by molecular beam epitaxy (MBE) on InP substrates. The resu lt of the modelling process enables a quantitative and objective deter mination of the intermixing at InAs/GaAs interfaces in relation to the MBE growth parameters which can be transferred to any other laborator y.