Investigation of InGaP/GaAs double-delta-doped heterojunction bipolar transistor

The double-delta-doped heterojunction bipolar transistor is successfully fabricated with improved current-voltage characteristics by employing the insertion of delta-doped sheets at emitter-base (E-B) and base-collector (B-C) heterojunction. Because of the use of delta-doped sheets, the potential spikes at E-B and B-C heterojunction are suppressed substantially. Thus a higher emitter injection efficiency (current gain) and a lower knee voltage are obtained. From experimental results, it is shown that the studied device is a good candidate for high-speed and high-power circuit applications.