Precise physical modeling of the reverse-short-channel effect for circuit simulation

A physical based threshold voltage model for circuit simulation is developed. The conventional short-channel effect as well as the reverse-short-channel effect are included. The reverse-short-channel effect due to impurity pileup at the surface of the substrate is modeled by assuming a linear impurity profile as a function of depth. Measured threshold voltage dependence on the bulk voltage is used to determine the impurity profile. The physically based modeling of the reverse-short-channel effect enabled a short-channel effect description, which simply exploits the channel length dependence of the lateral electric field.