Using silicon device modeling techniques for GaAs devices

Numerical models have been developed for Si MOSFETs which achieve high accuracy and retain numerical stability and physical flexibility. The methods used in these models can be applied to GaAs MESFETs to yield a computer model which, retains the accuracy and robust numerical properties of two-dimensional Si MOSFET models yet retains most of the physical detail of Monte Carlo simulation. Two significant differences between this model and previous models appear. First, by incorporating interband scattering directly, high field regions of the device are seen to be controlled by alternate regions in which conduction by central valley and satellite valley electrons predominate. Second, the two-dimensional field shape in the part of the transistor between the gate and the drain is critical in calculating the interband scattering and in determining the average effective mobility.