On the Challenges of SiGe HBTs in Advanced BiCMOS Technology Toward Half THz fMAX

Advanced BiCMOS technology employing SiGe HBTs is a cost-effective candidate for a wide range of exciting applications including automotive radar and 5G wireless communications. In this paper, results from two experimental studies are presented in an advanced 90nm SiGe BiCMOS technology in production. One experiment reduces the collector-base capacitance, while the other reduces base resistance. Both experiments achieved 300GHz fT and met or exceeded the 360GHz fMAX goal of the technology. Furthermore, results from a series of experiments are also reviewed in this paper, showing paths toward SiGe HBTs of half THz fMAX and fT around 300 GHz, based on the same 90nm SiGe BiCMOS technology.