Modeling and simulation of GaAs MESFETs

A two-dimensional numerical simulator is introduced to study the performance of GaAs MESFETs. The system of equations to be solved includes Poisson´s and the continuity equations. The incomplete Choleski decomposition conjugate gradient method and the incomplete LU decomposition biconjugate gradient square method are selected to solve the linear systems resulting from the discretization of the equations. The two-dimensional distribution of the electrical potential and the electron concentration inside the device are presented. A new mobility model that accounts for surface effects is presented. The model alleviates a problem encountered in some existing simulators, namely the overestimation of the drain current at low drain source voltages. The Gummel method is selected for use in the numerical simulation. The predictions of the simulator are compared to experimental data