Emitter current-crowding in high-voltage transistors

The problem of emitter current-crowding is treated for the case where the base is heavily doped with respect to the collector and the transistor is operating in the quasisaturation region. Closed-form solutions for terminal currents and current gain are derived in terms of elliptic integrals and other related functions. Good agreement with experimental data is demonstrated and various design implications of the theory are discussed.