Table Lookup MOSFET Capacitance Model for Short-Channel Devices

Abstract

A charge-based table lookup MOSFET capacitance model is derived for a circuit simulation application. Measured C/sub gs/(V/sub ds/, V/sub gs/) and C/sub gd/(V/sub ds/, V/sub gs/) tables and a calculated Q(V/sub ds/, V/sub gs/) table are utilized for representing nonlinear MOSFET capacitance behavior. The substrate terminal effect for C/sub gs/ and C/sub 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.