The effects of carrier-concentration-dependent bandgap narrowing on bipolar-device characteristics

A modeling of carrier-concentration-dependent bandgap narrowing in silicon bipolar transistors is proposed. Using a two-dimensional numerical simulation program, the effects of this phenomenon on the bipolar-device characteristics under high-level injection conditions have been studied. Transistor β falloff slows down due to the carrier-concentration-dependent bandgap narrowing, whereas there is no appreciable effect on cutoff frequency fTversus Jccharacteristics.