Automated parameter extraction and modeling of the MOSFET below threshold

A subthreshold model for use in circuit simulation software is described. The model includes representation of nonuniform substrate impurity concentrations and short-channel and narrow-channel effects, while being simple in form. It has been developed in concert with an automated parameter-extraction methodology. The model adds only one parameter to the existing strong inversion model with which it is fully integrated. The accuracy and computational efficiency are suitable for circuit simulation. The results of an extraction carried out on nMOS transistors with channel widths from 70 to 0.9 mu m and channel lengths from 35 to 1.25 mu m over a wide range of bias conditions are described. >