Gate-assisted turn-off effect in TIL-type thyristors

The research reported in this work was focused on the turnoff performance of trial high-power gate-assisted turn-off thyristors (GATT´s) based upon the novel double-interdigitated or two interdigitation levels (TIL) gate-cathode concept. The experiments were performed on high-voltage (2000 V) devices which were driven up to an anode current ofi_{T} = 500A. The test TIL GATT´s were both gold-doped and normal (nongold,diffused). The investigations have shown that the application of a negative gate current of only 4 A leads to a reduction of the turn-off time iqby a factor of 3 and 4-4.5 in gold-doped and normal devices, respectively, at Tj= 100°C. At constant gate current, the dependence of tqon the anode current level tTwas found relatively weak. The additional experimental data provided in this work show clearly that sought-for benefits could be achieved by implementing the TIL pattern in power GATTs.