ABSTRACT
Strained InGaAs quantum layers grown on V-groove GaAs substrates show composition variations across the growth front. Furthermore, the quantum wire (QWR) that is formed in the groove centre reveals a complex composition distribution. We have developed and refined two methods for the characterization of InGaAs/GaAs QWRs, quantitative EELS spectrum imaging and quantitative (200) dark field imaging. In order to interpret the dark field contrast in these non-planar structures, the strain profile was simulated using a finite element calculation and a subsequent dynamical contrast calculation results in the desired image contrast. From the correlation of these simulations with the experimental dark field images we can distinguish between strain and chemical contrast in the images. Both techniques are used to understand the influence of In on growth and luminescence properties.
