Realising wide bandgap P-SiC-emitter lateral heterojunction bipolar transistors with low collector-emitter offset voltage and high current gain: a novel proposal using numerical simulation

The authors report a novel method to reduce the collector-emitter offset voltage of the wide bandgap SiC-P-emitter lateral HBTs using a dual-bandgap emitter. In their approach, the collector-emitter offset voltage V_CE(offset) is reduced drastically by eliminating the built-in potential difference between the emitter-base (EB) and collector-base (CB) junctions by using a SiC-on-Si P-emitter. It is demonstrated that the proposed dual-bandgap P-emitter HBT, together with the SiGe base and Schottky collector, not only has a very low V_CE(offset) but also exhibits high current gain, reduced Kirk effect, excellent transient response and high cutoff frequency. The performance of the proposed device is evaluated in detail using two-dimensional device simulation, and a possible BiCMOS compatible fabrication procedure is also suggested.