A selective epitaxy collector module for high-speed Si/SiGe:C HBTs

This paper presents the results of investigations on high-speed self-aligned Si/SiGe:C HBTs featuring a selective epitaxial growth of the collector. We detail the dc and ac characteristics of the devices and demonstrate the improvement of the control of doping profiles at the base/collector junction. State-of-the-art fT value of 350 GHz has been achieved, the fT BVCEO product being equal to 525 GHz. V.