Numerical simulation of the GTO thyristor

2D numerical simulation results are presented for realistic GTO thyristor structures, including planar- and mesa-cathode configurations. Steady-state results include effects of lifetime reduction on forward conduction. Analysis of the transient gate turn-off process under different circuit conditions provides new insight into device operation. In the storage period, at high current levels, desaturation can no longer be neglected as against plasma pinching time; the two mechanisms depend differently on gate current. A new definition of the on-region width, based on relative current density, characterizes the region of high power dissipation during fall-time. Most switching energy is, however, lost during the slow tail period, where the time constant depends for comparable parts on carrier transport and recombination.