A submicrometer 252 GHz f sub(T) and 283 GHz f sub(MAX) InP DHBT with reduced C sub(BC) using selectively implanted buried subcollector (SIBS)

The selectively implanted buried subcollector (SIBS) is a method to decouple the intrinsic and extrinsic C sub(BC) of InP-based double-heterojunction bipolar transistors (DHBTs). Similar to the selectively implanted collector (SIC) used in Si-based bipolar junction transistors (BJTs) and HBTs, ion implantation is used to create a N+ region in the collector directly under the emitter. By moving the subcollector boundary closer to the BC junction, SIBS allows the intrinsic collector to be thin, reducing tau sub(C), while simultaneously allowing the extrinsic collector to be thick, reducing C sub(BC). For a 0.35 6 mu m super(2) emitter InP-based DHBT with a SIBS, 6 fF total C sub(BC) and >6 V BV sub(CBO) were obtained with a 110-nm intrinsic collector thickness. A maximum f sub(T) of 252 GHz and f sub(MAX) of 283 GHz were obtained at a V sub(CE) of 1.6 V and I sub(C) of 7.52 mA. Despite ion implantation and materials regrowth during device fabrication, a base and collector current ideality factor of similar to 2.0 and similar to 1.4, respectively, at an I sub(C) of 100 mu A, and a peak dc beta of 36 were measured.