A Novel Diode-Clamped Carrier Stored Trench IGBT With Improved Performances

In this article, a novel diode-clamped carrier stored trench IGBT (DC-CS-TIGBT) is proposed and investigated by the TCAD tool. Two series-connected diodes implemented on the surface of the IGBT is proposed to clamp the voltage potential of the carrier stored layer (CSL). Hence, the CSL can be heavily doped. A significant improvement in the tradeoff between ON-state voltage ( $V_{ \mathrm{\scriptscriptstyle ON}}$ ) and turn-off loss ( $E_{ \mathrm{\scriptscriptstyle OFF}}$ ) can be achieved due to enhanced emitter injection. Moreover, due to the shielding effect on the voltage potential of the CSL, the saturation current is reduced by over 41% compared with that of the buried P-shield CS-TIGBT(PS-CS-TIGBT). Consequently, the withstand time of short-circuit is improved from 6.7 to $15~\mu \text{s}$ compared with that of the PS-CS-TIGBT.