Optimum profiles for low-noise ion-implanted GaAs MESFETs

The noise and RF performance of recessed-gate GaAs ion-implanted MESFETs as a function of various doping profiles has been theoretically investigated. The effects of implant energy and dose as well as varying deep-level concentration are included. Degradation of device performance with increasing deep-level concentration is predicted and the responsible physical mechanisms revealed. Also, an optimum gate recess depth is shown to exist. The study has indicated a number of design rules for the fabrication of optimized, low-noise ion-implanted MESFETs.