Compact physical models for gate charge and gate capacitances of AlGaN/GaN HEMTs

This work presents a physical analytical model for the total gate charge and C-V characteristics of AlGaN/GaN HEMT devices. A continuous analytical model of the gate-charge is developed first, based on an assumption of considering only the first energy level in the triangular quantum well approximation at the AlGaN/GaN interface where most of charge carriers reside. The gate-source and the gate-drain capacitances are then obtained through differentiation of the gate charge at the corresponding terminal voltages. Excellent agreements between the modeled and measured C-V characteristics of a device were obtained.