Characterization of base parasitic resistance in analog bipolar transistors

The base current dependency of parasitic base resistance of analog bipolar transistors is discussed. A finite-difference analysis technique is used to examine the relationship between R_b and emitter current crowding, base conductivity modulation, and Kirk effect. It simulates base parasitic resistance of bipolar transistors in all current levels. The method is illustrated using an advanced analog bipolar transistor with a heavily doped emitter. Results of this research have been used to develop high-frequency, high-performance bipolar transistors used in recently developed linear products