The dV/dt capability of double-interdigitated (TIL) thyristors

This work presents an alternative solution, with respect to the conventional cathode-emitter shorts or MOS-controlled emitter shorts, for achieving virtual immunity to the parasitic action of displacement currents in power thyristors. The developed simple design/ technological procedure, based upon the novel double-interdigitated or two interdigitation level (TIL) gate-cathode configuration with a coarse geometry, offers a fair balance between technological simplicity/cost effectiveness and overall device performance. Based upon the developed design guidelines, two sets of gold-doped thyristors with different geometrical configurations and current-voltage handling capabilities were produced. The performed measurements have shown that both sets of TIL thyristors possess an extremely high value of the maximum permissible critical rate of rise of the off-state voltage (dV/ dt capability) even under open-gate conditions. When the gate is connected to the cathode, the TIL thyristors are practically immune to the action of displacement currents. Unlike thyristors using conventional emitter shorts, the TIL-type devices possess a good static and dynamic turn-on/latching sensitivity and have low on-state losses at high-current densities.