A new approach to optimizing the base profile for high-speed bipolar transistors

It is shown using first-order analytical analysis and extensive device simulations that, for a given base resistance and peak base doping, a uniform base profile gives a higher cutoff frequency than a graded profile. This result is explained by the narrower base width that can be achieved with a uniform profile, which more than compensates for the lack of the aiding electric field present in graded-base transistors.<
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