EXTRACTION OF DC BASE PARASITIC RESISTANCE OF BIPOLAR-TRANSISTORS BASED ON IMPACT-IONIZATION-INDUCED BASE CURRENT REVERSAL

A new method for the evaluation of the dc base parasitic resistance, R (B), of bipolar transistors is described. The method is based on impac t-ionization-induced base current reversal and enables R(B) to be eval uated independently from the emitter parasitic resistance in a wide ra nge of emitter current and collector-base voltage, without requiring a ny special device structure. The method can also extract R(B) in impac t-ionization regime, where current crowding due to negative base curre nt induces an increase in R(B) at increasing emitter current.