Trench gate emitter switched thyristors

Abstract

A new MOS-gated Emitter Switched Thyristor (EST) structure using trench gate technology is reported for the first time. In this new trench gate EST, the voltage drop across the series lateral MOSFET is reduced due to an increase in channel density resulting in forward voltage drops equal to thyristors and MCTs. In addition, the parasitic thyristor that is inherent in the conventional EST is completely eliminated in this structure, allowing higher maximum controllable current densities for ESTs. The trench gate allows homogenous current distribution in the EST and preserves the unique feature of gate controlled current saturation of the thyristor current. The characteristics of 600 V forward blocking trench EST obtained from two dimensional numerical simulations is described and compared with that of the trench IGBT and MCT. Resistive load simulations for the trench EST indicate turn-off times comparable to trench IGBTs and MCTs.