Applied Physics Letters · 1993 · 359 citations · 12 references
EngineeringElectrical EngineeringMaterials ScienceMicroelectronicsSemiconductor DevicesSemiconductor MaterialsField-effect TransistorsMetal-semiconductor ContactsSemiconductor Device MaterialsSemiconductor PhysicsWide-bandgap Semiconductor DevicesWide-bandgap SemiconductorsField-effect Transistor Transfer CharacteristicsGallium Nitride (Gan) MaterialsMetal-semiconductor Field-effect TransistorsOhmic ConductionOhmic ContactsOhmic MaterialsSapphire Substrate PreparationSchottky Barriers
In this letter we report the fabrication and characterization of a metal semiconductor field effect transistor (MESFET) based on single crystal GaN. The GaN layer was deposited over sapphire substrate using low pressure metalorganic chemical vapor deposition. MESFET devices were fabricated on isolated mesas using TiAu for the source and drain ohmic contacts and silver for the gate Schottky. For devices with a gate length of 4 μm (channel opening, i.e., source to drain separation of 10 μm), a transconductance of 23 mS/mm was obtained at −1 V gate bias. Complete pinch-off was observed for a gate potential of −12 V.
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