Effect of collector lateral scaling on performance of high-speed SiGe HBTs with f_T > 300 GHz

摘要

The effect of collector lateral scaling on the performance of 300 GHz-level SiGe HBTs is investigated. Peak f_T and f_(max) exhibited an initial improvement followed by a degradation with decreasing collector width. Possible causes behind the observed trend are discussed in terms of RC delay and the Kirk effect.