Atomic-scale imaging of dopant atoms in Si-doped GaN

Determination of the concentration and distribution of trace impurity is a key factor in the manufacture of advanced semiconductor materials and is of great significance to the development of sophisticated electronics. Doping has a great influence on the performance of GaN, and a small change in the impurity content will lead to the degradation of the device performance, or even cause device failure. Determining the trace impurity and spatial distribution is therefore critical to understanding and adequately tuning functional properties. In this study, the two-dimensional distribution of Si-doped in GaN was determined by atomic resolution scanning transmission electron microscopy high angle annular dark field (STEM-HAADF) image combined with EDS mapping. Furthermore, STEM image simulation was used to estimate the distribution of trace impurity in the depth direction. This method may be useful for the determination of trace impurity concentration and distribution in semiconductor materials.