Subthreshold characteristics of insulated-gate field-effect transistors

A simple analytical model is developed for the subthreshold region of insulated-gate field-effect transistors (IGFET). For short channels, it is necessary to extend the model to include two-dimensional band-bending effects at the source in order to describe correctly the reduction in threshold caused by high drain and substrate voltages. The model is experimentally verified over a wide range of bias conditions and channel lengths and is compared with one- and two-dimensional numerical models.