Random telegraphic signals in silicon bipolar junction transistors

Random telegraphic signals (RTS) are observed in the forward-biased dc base current of electrically stressed silicon bipolar transistors. The RTS noise in the base current is shown to originate from random trapping of electrons at the stress-created oxide and interface traps located over the oxide-covered emitter-base junction space-charge region. The observed pulse width (∼0.1–100 s), the uniform height of the pulses (∼1% of dc base current), and their dependencies on temperature and VBE (emitter/base bias voltage), exp(qVBE/nkT) with n=2, are interpreted by the two-step model consisting of electron tunneling between the oxide and interface traps, and the recombination of Si band electrons and holes at the interface traps.