Composition determination of multinary III/V semiconductors via STEM HAADF multislice simulations.

Knowledge of the microscopic elemental composition of multinary III/V semiconductor materials is crucial to the development of functionalized opto-electronic devices. Well-proven composition analysis methods, such as high resolution X-ray diffraction (HRXRD), fail to determine the elemental composition when more than three atomic species are involved. In this work we propose a procedure for the composition analysis of multinary III/V semiconductors at atomic resolution using high angle annular dark field (HAADF) scanning transmission electron microscopy (STEM) image simulations. Our method exploits the dependence of HAADF-STEM image intensities on the atomic number and static atomic displacements (SAD) at different detector inner angles. Here, we describe the proposed method in detail using Ga(NAsP) as an example multinary material.