A NEW NUMERICAL-METHOD FOR QUASI-3-DIMENSIONAL SMALL-SIGNAL SIMULATION OF SILICON BIPOLAR-TRANSISTORS

A new approach to modeling the high-frequency (h.f.) small-signal char acteristics of a real three-dimensional bipolar transistor (BJT) is pr esented. It is based on the joint use of the BIPOLE3 program[1] and a special code HFCALC. First, BIPOLE3 calculates the DC electric field a nd carrier distributions in the vertical direction and the DC potentia l distribution in the base region in a horizontal plane. Then HFCALC c alculates the vertical one-dimensional (1D) AC potential and carrier d istributions and identifies the parameters of the small-signal one-dim ensional hybrid-pi BJT model for each section of the distributed AC mo del of intrinsic BJT region. Finally, it performs a circuit analysis f or this distributed model plus external elements. As a result, current gain, Y, S and the other AC parameters are computed versus frequency under given DC bias conditions. Copyright (C) 1996 Elsevier Science Lt d