Separate-Bottom Player CSTBT™ for Approaching Turn-off Switching Loss Reduction Limit

Abstract

The dynamic avalanche restricts the turn-off switching speed and limits $E_{\text{off}}$ reduction. In this paper, we propose a new separate-bottom Player CSTBT™ and demonstrate its impact on $E_{\text{off}}$ reduction by TCAD simulations. This structure relaxes the electric field at trench bottom and enables faster $\mathrm{d}I/\mathrm{d}t$ and $\mathrm{d}V/\mathrm{d}t$. Therefore, our proposed structure successfully reduces the $E_{\text{off}}$ by 20% at the same condition of $V_{\text{CE}(\text{sat})}$ as the conventional structure, approaching the $E_{\text{off}}$ limit.