A ROBUST AND PHYSICAL BSIM3 NON-QUASI-STATIC TRANSIENT AND AC SMALL-SIGNAL MODEL FOR CIRCUIT SIMULATION

A new non-quasi-static (NQS) MOSFET model, which is applicable for bot h large-signal transient and small-signal sc analysis, has been develo ped. It employs a physical relaxation time approach to take care of th e finite channel charging time to reach equilibrium and the effect of instantaneous channel charge re-distribution, The NQS model ir formula ted independently from the de I-Tr and the charge-capacitor model, thu s can be easily applied to any existing simulators. The model has been implemented in the newly released BSIM3 version 3, anti comparison ha s been made among this model, common quasi-static (QS) SPICE models an d PISCES two-dimensional (2-D) numerical device simulator, While predi cting accurate NQS behavior, the time penalty for using :he new model is only about 20-30% more than the common QS models, it is much less t han the time required by other NQS models reported. Limitations and co mpromises between simplicity, efficiency and accuracy are also discuss ed.