Optimization of GaAs power MESFET device and material parameters for 15-GHz operation

The results of recent 15-GHz measurements on GaAs power FET´s are described. The microwave performance has been determined as a function of epitaxial doping level and thickness, gate recess depth, gate finger width, and source-drain spacing. The optimum values of these parameters for 15-GHz operation are epitaxial doping level approximately 1.6 × 10¹⁷cm^-3, saturated drain current with zero gate voltage in the range 330- to 400-mA/mm gatewidth, gate recess depth between 500 and 1000 Å, gate finger width ≤ 150 µm, and source-drain spacing approximately 5 µm.