An efficient model for trap analysis in C-V measurement for AlGaN/GaN heterostructure

In this work, we propose an improved small signal equivalent capacitance-voltage (C-V) model to eliminate frequency dispersion in measurement for the AlGaN/GaN heterostructure, and then we calculate the trap density in the buffer layer. Compared with photoluminescence (PL) and high resolution X-ray power diffraction (HRXRD) data, it reveals that the main component of trap is made up of the point defect. Fluorine treatment is done in one sample, positive shift of the pinch-off voltage shows that the F ions have injected into the sample effectively, and the dramatic drop of trap density shows that gallium vacancies is the main component of the trap. All this result shows the advantage of the improved model on the analysis of the trap behavior in the AlGaN/GaN heterostructure.