This paper deals with SiGe HBTs optimization for power amplifier applications dedicated to Bag wireless communications.In this work, we investigate the fT-BVCEO tradeoff by various collector optimization schemes such as epilayer thickness and dopant concentration, and SIC and CAP characteristics.Furthermore, a new trapezoidal base Germanium (Ge) profile is proposed.
Thanks to this profile, precise control of Ge content at the metallurgical emitter-base junction is obtained.Gain stability is obtained for a wide range of temperatures through tuning drive board wire the emitter-base junction Ge percent.Finally, a comprehensive investigation of Ge introduction into the collector (backside Ge profile) is conducted in order to improve the fT values at high injection levels.