Impact of profile scaling on high-injection barrier effects in advanced UHV/CVD SiGe HBTs

We present the first comprehensive investigation of the impact of Ge profile shape as well as the scaling of collector and base doping profiles on high-injection heterojunction barrier effects in advanced UHV/CVD SiGe HBTs over the temperature range of -73/spl deg/C to 85/spl deg/C. Results indicate that careful Ge profile design tailored with a proper collector profile design are required to push the barrier onset current density (J/sub C,barrier/) to well beyond the typical circuit operating point.