Impact of the collector structure on the performance of the insulated gate bipolar transistor

Various types of collectors have been reported for insulated-gate bipolar transistors (IGBTs). Despite their importance however, a thorough study on the influence of the collector structure on the performance of the IGBT is lacking in literature. In this work, the impact of the collector structure on mainly the DC performance of the IGBT has been studied through extensive TCAD simulations. This is done via the Gummel number of the collector, which is used for three types of collector structures ( i.e. silicon, silicon-germanium, and pure boron). These structures are interesting because they can extend the Gummel numbers to respectively smaller and higher values, and potentially also reduce the process complexity. Finally, an analytical expression between the saturation voltage and stored charge, i.e. the trade-off curve, has been derived, where the stored charge is a good measure for the switching losses. Therefore, this analytical expression can be employed to estimate the switching losses directly from device properties.