High-voltage current saturation in emitter switched thyristors

Current saturation at high voltages in MOS-gated emitter switched thyristors (ESTs) is demonstrated. It is shown that by using an improved EST structure containing a dual-channel lateral MOSFET, the thyristor current can be saturated to high voltages through MOS gate control. In experimental devices with 600-V forward blocking capability, it is observed that current densities of 110 A/cm/sup 2/ could be saturated up to 450 V with a gate bias of 3.5 V. Experimental measurements and numerical simulations indicate that, during current saturation, the voltage appears across the junction between the P-base region and the N/sup -/ drift region and not across the lateral MOSFET.<
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