MODELING THE ANOMALOUS THRESHOLD VOLTAGE BEHAVIOR OF SUBMICROMETER MOSFETS

This paper reports a simple yet accurate semi-empirical analytical model for simulating the anomalous threshold voltage behavior in submicrometer MOSFET's. The increase in the threshold voltage with decreasing channel length has been modeled by assuming a bias-independent, but channel-length-dependent, fixed charge at the source and drain ends. The new model requires two extra parameters in addition to the usual short-channel threshold voltage model parameters. These two parameters represent the magnitude of the fixed charge and the length over which the charge is spread at the source and drain ends. The model shows excellent agreement with the experimental threshold voltage data (within 2%) for submicrometer devices with varying oxide thickness, junction depth, and channel doping concentration.