Low Turn-Off Loss 4H-SiC Insulated Gate Bipolar Transistor With a Trench Heterojunction Collector

Ying Wang,Hong-Kai Mao,Jian-Qun Yang,Cheng-Hao Yu,Fang-Wen Su,Xue Wu,Xing-Ji Li

doi:10.1109/jeds.2020.3022571

Abstract

In this work, an improved 4H-SiC insulated gate bipolar transistor (IGBT), or CTH-IGBT, with a trench p-polySi/p-SiC heterojunction on the backside of the device is proposed to reduce the turn-off energy loss ( $E_{off}$ ) and turn-off time ( $T_{off}$ ). The electrical properties of the proposed and contrast structures are all simulated using the ATLAS simulation software to research the working mechanism of this improved structure. For the static performance, the specific ON-resistance ( $R_{on,sp}$ ) and the figure of merit ( ${\mathrm{ FOM}} = V_{BR}^{2}/ R_{on,sp}$ ) are not influenced much as compared to the traditional structure at the same breakdown voltage ( $V_{BR}$ ) of 12 kV. However, with a prominent electron current path formed by the heterojunction region of CTH-IGBT, a very available conduction path to discharge the electrons during turn-off process is proved in this article. The simulation results demonstrate that compared with the traditional structure, the turn-off energy loss of the CTH-IGBT is reduced by 76.4%, while the turn-off time is reduced by 85.0%.

Highlights

The performance of silicon-based devices is gradually approaching its limits, and it has become increasingly difficult to meet the application requirements of modern power electronic systems
The results show that under the same breakdown voltage of 12 kV, the turn-off energy loss of the CTH-insulated gate bipolar transistor (IGBT) is 76.4% lower than the conventional IGBT (C-IGBT), and the turn-off time (Toff ) is reduced by 85.0%
It can be seen that when the devices undergo its avalanche breakdown voltage, the internal electric field peaks all appear at the corner of P+shielding region below the trench gate

Summary

Introduction

The performance of silicon-based devices is gradually approaching its limits, and it has become increasingly difficult to meet the application requirements of modern power electronic systems. INDEX TERMS 4H-SiC, heterojunction, insulated gate bipolar transistor (IGBT), turn-off loss, turn-off time, breakdown voltage. In order to further reduce the turn-off energy loss, without sacrificing the static characteristics, we have proposed the collector trench heterojunction IGBT (CTH-IGBT) with a p-polySi/p-SiC trench heterojunction on the backside of

Results

Conclusion