AN IMPROVED DC MODEL FOR CIRCUIT ANALYSIS PROGRAMS FOR SUBMICRON GAAS-MESFET

An improved submicron GaAs MESFET model is presented which is suitable for nonlinear small-signal circuit designs. The Kacprzak-Materka mode l, which simulates the de characteristics of large signal devices has been modified to predict the behavior of submicron devices, In this mo dification the concept of a shift in threshold voltage has been introd uced. It has been shown that without taking into account the shift whi ch is caused by the submicron geometry it is not possible to predict t he device characteristics. Small-signal devices of different aspect ra tio have been modeled with greater accuracy than that of other models. As far as possible we have determined the model parameters from the d e,ice physics and established the advantages of this approach over ter minal methods, The modified model should be a useful tool for the desi gning of future integrated circuits with submicron gate length MESFET' s.