IEEE Electron Device Letters · 1984 · 25 citations · 0 references
EngineeringElectrical EngineeringMaterials ScienceMicroelectronicsMicrowave EngineeringSemiconductor DevicesHigh-frequency Semiconductor DevicesMicrowave Semiconductor DevicesSemiconductor Device MaterialsWide Band Gap SemiconductorsWide-bandgap Semiconductor DevicesWide-bandgap SemiconductorsBand GapBreakdown VoltageGainGate LeakageGate Leakage CurrentMicrowave DevicesPower Added EfficiencyRadio-frequency Devices
A metal-insulator-semiconductor field-effect transistor using an undoped AlGaAs layer as an insulator has been fabricated and RF tested. Due to the higher breakdown field of the wide-band-gap AlGaAs, the gate breakdown voltage has been greatly improved as compared with a conventional GaAs MESFET. The prebreakdown gate leakage current of this new device structure is also much lower than that of the MESFET. The presence of the gate insulator also reduces the gate capacitance. All these factors result in a GaAs power FET structure with potentials for high power, efficiency, and frequency of operation. An unoptimized 750-µm gate-width device achieved an output power of 630 mW with 7-dB gain and 37-percent power-added efficiency at 10 GHz. At reduced output power levels, power-added efficiency as high as 46-percent was obtained at X-band.