Design of PNP SiGe HBTs Towards 200 GHz f_max

Engineering SiGe HBTs with very high f T and f max poses a significant challenge in the industry. Most technology iterations focus primarily on the improvement of the NPN performance for RF amplifiers, and a fast PNP device is often never offered. It is even more difficult to make high performance SiGe PNP transistors with comparable performance due to fundamental material and electrical limitations. However, the availability of a complementary device can enable several circuit applications including matched driver circuits and push-pull amplifiers. This paper applies lateral and vertical optimizations in a SiGe PNP, explores the performance scaling available and demonstrates a measured peak f T / f max performance of 130/180 GHz at a BV CBO of 5.1 V.