Double-interdigitated (TIL) bipolar power transistors with lightly doped collectors

The results of an investigation concerning the implementation of the two-interdigitation-level (TIL) concept in TO-3-packaged, triple-diffused bipolar power n-p-n transistors with lightly doped collector are discussed. It is demonstrated that the TIL concept, which offers a fair balance between manufacturability ease/cost effectiveness and overall electrical performances, allows for an increase of both the DC and small-signal current gains and the voltage ratings of bipolar transistors. The peculiarities of the ON-state current carrying mechanism in TIL-type transistors was investigated and its impact on device behavior was also assessed.