SiC Fin-Shaped Gate Trench MOSFET with Integrated Schottky Diode.

Xiaochuan Deng,Songjun Li,Ling Li,Xuan Li,Hao Wu,Rui Liu

doi:10.3390/ma14227096

Abstract

A silicon carbide (SiC) trench MOSFET featuring fin-shaped gate and integrated Schottky barrier diode under split P type shield (SPS) protection (FS-TMOS) is proposed by finite element modeling. The physical mechanism of FS-TMOS is studied comprehensively in terms of fundamental (blocking, conduction, and dynamic) performance and transient extreme stress reliability. The fin-shaped gate on the sidewall of the trench and integrated Schottky diode at the bottom of trench aim to the reduction of gate charge and improvement on the third quadrant performance, respectively. The SPS region is fully utilized to suppress excessive electric field both at trench oxide and Schottky contact when OFF-state. Compared with conventional trench MOSFET (C-TMOS), the gate charge, Miller charge, Von at third quadrant, Ron,sp·Qgd, and Ron,sp·Qg of FS-TMOS are significantly reduced by 34%, 20%, 65%, 0.1%, and 14%, respectively. Furthermore, short-circuit and avalanche capabilities are discussed, verifying the FS-TMOS is more robust than C-TMOS. It suggests that the proposed FS-TMOS is a promising candidate for next-generation high efficiency and high-power density applications.

Highlights

Silicon carbide (SiC) is an emerging material for power semiconductors with both competitive electric and thermal advantages
In order to solve these issues, several solutions are proposed at device level: (1) whole P+ shield region implanted at the bottom of trench [7]; (2) P+ shield region under the recessed source region [8], (3) buried P+ region in the drift region of trench metal oxide semiconductor field effect transistor (MOSFET) [9], (4) deep P base region using ultra-high implantation energy [10], (5) P+ shield region under the part of trench bottom [11], and (6) ground/floating split P+ shield region under the bottom of trench [12]
A silicon carbide (SiC) fin-shaped gate trench MOSFET with integrated Schottky diode (FS-TMOS) is proposed, and its physical mechanism is investigated in terms of static and dynamic performance with Technology Computer-aided Design (TCAD) Sentaurus

Summary

Introduction

Silicon carbide (SiC) is an emerging material for power semiconductors with both competitive electric and thermal advantages. This enables SiC central to medium-high voltage power device technology area, where SiC based metal oxide semiconductor field effect transistor (MOSFET) is considered to be the next-generation prime switching device candidate for various applications involving uninterruptible power supply (UPS), photovoltaic (PV) inverter, electric vehicle, etc. The trench gate brings considerable switching loss, which restricts the dynamic advantage of SiC MOSFET [6]. A SiC fin-shaped gate trench MOSFET with integrated Schottky diode (FS-TMOS) is proposed, and its physical mechanism is investigated in terms of static and dynamic performance with TCAD Sentaurus. The transient extreme stress is considered, involving short-circuit and avalanche capabilities

Structure and Mechanism

Results and Discussion

Conclusions