An improved DC model for circuit analysis programs for submicron GaAs MESFET's

An improved submicron GaAs MESFET model is presented which is suitable for nonlinear small-signal circuit designs. The Kacprzak-Materka model, which simulates the dc characteristics of large signal devices has been modified to predict the behavior of submicron devices. In this modification the concept of a shift in threshold voltage has been introduced. It has been shown that without taking into account the shift which is caused by the submicron geometry it is not possible to predict the device characteristics. Small-signal devices of different aspect ratio have been modeled with greater accuracy than that of other models. As far as possible we have determined the model parameters from the device physics and established the advantages of this approach over terminal methods. The modified model should be a useful tool for the designing of future integrated circuits with submicron gate length MESFET's.