Analysis and Modeling of Intrinsic Capacitance in Enhancement Mode GaN HEMT

This paper analyzes the intrinsic capacitance of enhancement-mode (e-mode) Gallium Nitridebased High Electron Mobility Transistor (GaN HEMTs). The intrinsic capacitance was measured using C_{i s s} (input capacitance), C_{o s s} (output capacitance), and C_{r s s} (reverse transfer capacitance). The C_{o s s} was also analyzed. Based on depletion-mode (d-mode) measurement data from the MIT virtual source GaN HEMT (MVSG) compact model, a measurement circuit for C_{i s s}, C_{o s s} and C_{r s s} was constructed and calibrated for reliability. Subsequently, the circuit, initially configured for d-mode GaN HEMT intrinsic capacitance measurements, was optimized for e-mode GaN HEMT, upon which intrinsic capacitance was measured. The influence on the graph was analyzed by varying parameters in the measured capacitance data, leading to the modeling of intrinsic capacitance.