Comprehensive Characterization of MOSFET Intrinsic Capacitances

The intrinsic capacitances of field effect transistors such as MOSFETs largely determine the switching speed and transient behavior of these devices. Proper representations of these non-linear capacitances are needed to develop accurate simulation models and to improve understanding of the device behavior. This paper presents a holistic representation of device capacitances that considers the influence of both the gate-source voltage (V
GS
) bias and drain-source voltage (V
DS
) bias. This analysis is applied to both a Silicon Carbide (SiC) MOSFET and a low-voltage Silicon (Si) MOSFET. These devices have similar physical structures but demonstrate significant differences in terms of their intrinsic capacitance profiles. A methodology for implementing the proposed bias-dependent capacitor model in the SPICE environment is proposed and validated with experimental data as part of this work.