Influence of the Ge profile on VBE and current gain mismatch in Advanced SiGe BICMOS NPN HBT with 200 GHz fT

Transistor mismatch is a key parameter for the design and operation of advanced analog circuits. The paper presents for the first time data from several generations of BiCMOS technology nodes for V_BE and current gain (beta) mismatch. The authors show that the 0.12 mum BiCMOS has a 3-a V_BE mismatch of 0.63 mV-mum and beta mismatch of 0.24 %-mum. CBE NPNs have essentially the same but slightly lower mismatch than CBEBC NPNs. Very small and very long devices have increased mismatch, especially at high currents. The authors also present a physical model and experimental data showing the influence of the emitter-base Ge slope on the device mismatch