Optimization of a SiGe:C HBT in a BiCMOS technology for low power wireless applications

The performance enhancement of a SiGe:C HBT for RF/IF applications is described for Motorola's 0.35 /spl mu/m and 0.18 /spl mu/m BiCMOS technologies. Cutoff frequencies (f/sub T/) have been improved from 50 GHz to 78/84 GHz (0.35/0.18 /spl mu/m BiCMOS), with a reduction in minimum noise figure (NF) from 0.7 dB to 0.30 dB. Improvements occurred through the optimization of the intrinsic collector and base dopant profiles, extrinsic collector resistance, and device layout.