Emitter-Base Breakdown: Measurement and Simulation

In order to decrease the base width of a bipolar transistor while maintaining acceptably low base resistance, the doping concentration in the base region must be increased. This, however, can lead to unacceptably low emitter-base reverse breakdown characteristics. The optimization of this trade-off recquires very accurate two dimensional process and device simulation programs. Currently, the models in most device simulation programs cannot accurately describe the reverse leakage characteristics of emitter-base Junctions. This paper introduces an accurate model for these effects by including band-to-band tunneling (BBT) in the carrier generation model. This makes it possible to optimize the trade-off between low base resistance and high emitter-base breakdown voltage through the use of process and device simulation programs.