Table Lookup MOSFET Capacitance Model for Short-Channel Devices

A charge-based table lookup MOSFET capacitance model is derived for a circuit simulation application. Measured C_gs(V_ds, V_gs) and C_gd(V_ds, V_gs) tables and a calculated Q(V_ds, V_gs) table are utilized for representing nonlinear MOSFET capacitance behavior. The substrate terminal effect for C_gs and C_gd is expressed by using the plural sets of charge and capacitance tables, in which each set is defined at a specified substrate voltage. Not only the short-channel effect, but also the subthreshold capacitance characteristics, can be accurately modeled by the experimental data without any analytical approximations.