REALIZATION OF AN N-CHANNEL GAAS ALGAAS BISTABLE FIELD-EFFECT TRANSISTOR (BISFET)/

The first realization of a novel heterostructure device, the bistable field-effect transistor (BISFET), is reported. The device uses an n-ch annel GaAs/AlGaAs inversion channel (IC) structure. It contains a posi tive feedback loop between the gate and source terminals, which is act ivated above a gate voltage of 1.7 V. This leads to abrupt transitions between high and low current states as the drain voltage is changed, with a switching ratio of 1.5. The transitions are accompanied by shar p changes in gate current as the feedback loop turns on and off. These transitions, referred to as switchup and switchdown, form a large hys teresis loop in the drain characteristics. Hysteresis as large as 3.7 V is observed, making the device strongly bistable.