Encapsulated GaAs power MESFET

Utilizing a combination of low-temperature-grown Al/sub 0.3/Ga/sub 0.7/As passivation, overlapping gate, MOCVD regrowth of the source/drain contacts, and isolation by boron ion implantation, we have fabricated a GaAs MESFET with a completely encapsulated channel. Electrical characterization of the device shows that the early catastrophic on-state breakdown is suppressed. In contrast to the usually observed characteristics in GaAs MESFET, the breakdown locus of the device also has a positive slope. These improvements should allow us to bias the device at a higher operating point, thereby increasing the obtainable maximum output power in the device.<
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