AlGaAs/GaAs double-heterostructure-emitter bipolar transistor (DHEBT)

An AlGaAs/GaAs double-heterostructure-emitter bipolar transistor (DHEBT) fabricated by molecular beam epitaxy (MBE) is presented. The use of a structure symmetrical with respect to the base layer results in bidirectional transistor and switching behavior. Due to a significant area difference between emitter-base and base-collector junction, an asymmetrical property is observed. With an emitter edge-thinning design, the transistor performance may be further improved. A common-emitter current gain of up to 140 with a negligible collector-emitter offset voltage ( approximately 40 mV) is achieved. A bidirectional S-shaped negative-differential-resistance (NDA) phenomenon occurs at high V/sub CE/ bias voltage. The temperature dependence of the NDR is investigated. A three-terminal-controlled switching device is found to perform well when the control current is introduced into the base electrode.<
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