Simulation of Influence of AlGaN/GaN Heterojunction Parameters on Its Capacitance Curves

We used the solution of the Poisson equation together with the drift and diffusion equations to simulate precisely the voltage dependence of the AlGaN/GaN capacitor structure. We demonstrate the influence of the structure parameters like doping concentrations of AlGaN, Schottky barrier height, and the thickness of the AlGaN layer on resulting C-V curve of the heterojunction capacitor. Also the capacitance of the structure in forward bias was simulated and the capacitance peak that sometimes occurs in the measurements was identified.