An approach to quantitative compositional profiling at near-atomic resolution using high-angle annular dark field imaging

The compositional profile of a GaAs/Al0.6Ga0.4As interface is investigated through analysis of a high resolution high-angle annular dark field image. Image calculations are carried out using a multislice code that incorporates thermal diffuse scattering, and an algorithm is developed for quantitative matching between these images and the experimental image. The resulting compositional profile (with monolayer spatial resolution) is compared with an analogous quantitative chemical mapping experiment. The extension of this new technique to high resolution compositional mapping (in two dimensions) is briefly explored.