Physical models for bipolar device simulation and their effects on cutoff frequency

The effects of individual physical models on the bipolar AC characteristic, i.e., the cutoff frequency f/sub T/, have been investigated. It has been found that the model for the intrinsic carrier concentration has a negligible effect on the f/sub T/-I/sub C/ characteristics. The effects of the carrier mobility and the apparent bandgap narrowing on f/sub T/ are found to be different for a bipolar transistor device structure. A sufficient agreement between the simulation and measurement of the f/sub T/-I/sub C/ characteristics has been obtained using the proposed physical models.<
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