Use of a surrounding p-type ring to decrease backgate biasing in GaAs MESFET's

The sensitivity to backgate biasing of two MESFET designs, one with an implanted surrounding p-ring and one without, were compared. A highly resistive p-like surface layer, possibly arising from the uncapped anneal, is thought to be the agent of the backgating. The addition of the surrounding p-ring results in greatly decreased backgate biasing.