AlGaAs or InGaP low turn-on voltage GaAs-based heterojunction bipolar transistor

摘要

A heterojunction bipolar transistor is provided that has a reduced turn-on voltage threshold. A base spacer layer is provided and alternately an emitter layer is provided that has a lowered energy gap. The lowered energy gap of the base spacer or the emitter spacer allow the heterojunction bipolar transistor to realize a lower turn-on voltage threshold. The thickness of the emitter layer if utilized is kept to a minimum to reduce the associated space charge recombination current in the heterojunction bipolar transistor.