Hot-carrier effects on power characteristics of SiGe HBTs

This letter investigates hot-carrier (HC) effects on the power characteristics of Si-SiGe HBTs using load-pull measurements. We found that the output power, power gain, and linearity of Si-SiGe HBTs are degraded after HC stress. Under constant base-current measurement, the HC-induced power performance degradation is found to be much worse than that under constant collector-current measurement. The HC effects on the cutoff frequency, nonlinearity terms of base-current and collector-current, and third-order intermodulation (IM3) cancellation effect have been analyzed to explain the experimental observations.