Modeling of ion-implanted GaAs MESFET's by the finite-element method

We discuss the results of a new two-dimensional (2-D) finite-element model for GaAs MESFET's made by ion implantation. Several different devices are characterized by varying gate recess and doping profile. The simulation, in qualitative agreement with experimental findings, shows that a FET with a shallow gate recess exhibits a similar behavior to a FET with a deep implantation, i.e., an improvement in linearity, a higher pinch-off voltage, and a decrease in transconductance.