2-D characterization of dynamic charge distribution in MOS controlled thyristors: experiment and simulation

The MOS-controlled thyristor (MCT) is well suited for very high power applications. The maximum capability of turn-off currents for p-channel MCT's was so far limited to low values (<10 A at 1000 V snubberless switching) due to strong sublinear current scaling with respect to the device area. In this letter we investigate this phenomenon by full device scale transient carrier distribution measurements and simulations. For the first time the degradation of the switching performance for highly structured and shorted base MOS thyristors is related by measurement to an inhomogeneous current distribution in the device during switching. These measurements confirm predictions of the effect by device simulation.<
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