A Consistent Drain And Substrate Current Model Of LDD MOS Devices For Circuit Simulation

This paper describes a Spice-compatible circuit simulation model of submicron LDD MOS devices. It includes an enhanced model of our previous drain current characteristics (UNIMOS) and a new analytical substrate current model. For the drain current characteristics, new features of our previous model has been added for achieving good accuracy and convergency. In addition, the two-dimensional electric field distribution during impact ionization which has much more physical meaning is considered for developing the hot electron model. Thus, a new and accurate substrate current model is proposed based on the so called effactive electric field, instead of the conventional peak electric field concept used by the lucky-electron (LE) theory. Comparison of the modeled results with those of experiment shows excellent match for a wide range of device channel lengths and bias conditions.