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 VCE(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 VCE(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.
This paper can be downloaded from http://web.iitd.ac.in/~mamidala/id11.htm