High-performance collector-up InGaP/GaAs heterojunction bipolar transistor with Schottky contact

The first fabrication and RF characterisation of an InGaP/GaAs single heterojunction bipolar transistor in collector-up topology with Schottky contact are reported. Boron implantation is employed to prevent current injection into the extrinsic base region. Realised devices exhibit F/sub MAX/=110 GHz and breakdown voltage BV/sub CE0/=16 V. The RF gain of these components appears to be less sensitive to HBT development than standard emitter-up HBTs.