Px. Ma et al., An analytical model for space-charge region capacitance based on practicaldoping profiles under any bias conditions, SOL ST ELEC, 45(1), 2001, pp. 159-167
An analytical model is presented For quasi-static capacitance of the space-
charge region in a p-n junction. The model is valid for realistic junction
doping profiles under any bias conditions. It consists of local models in t
hree bias regions. For the high-reverse bias region, a novel analytical mod
el is derived. For the moderate-bias region, an empirical model commonly us
ed in SPICE is adopted. Finally, for the high-forward bias region, the junc
tion profiles are approximated by linearly-graded junctions. Existing analy
tical models are then modified appropriately to characterize both high-inje
ction and heavy-doping effects for advanced bipolar transistors. Compared t
o previously developed analytical models or existing empirical models, as w
ell as numerical simulation results, the analytical model presented here sh
ows an improved accuracy and therefore provides a better tool For both devi
ce and circuit simulations. (C) 2001 Elsevier Science Ltd. All rights reser
ved.