A dual trench gate emitter switched thyristor (DTG-EST) with dual trench gate electrode and different gate oxide thickness

In this paper, the dual trench gate emitter switched thyristor (DTG-EST) with dual trench gate electrode is proposed for improving snap-back effect which leads to a lot of problems in device applications. The parasitic thyristor which is inherent in the conventional EST is completely eliminated in this structure, allowing higher maximum controllable current densities for ESTs. The dual trench gate allows homogenous current distribution in the EST and preserves the unique feature of the gate controlled current saturation of the thyristor current. The conventional EST exhibits snap-back with anode voltage and current density of 2.73 V and 35 A/cm², respectively. The proposed DTG-EST exhibits snap-back with anode voltage and current density of 0.96 V and 100 A/cm², respectively. The saturated anode current density of the proposed DTG-EST at an anode voltage 9.6 V is 2388 A/cm ². The characteristics of the 600 V forward blocking DTG-EST obtained from two-dimensional numerical simulations (MEDICI) is described and compared with that of a conventional EST and a vertical trench gate EST.