Analysis of Electrical Characteristics in 4H-SiC Trench-Gate MOSFETs with Grounded Bottom Protection p-Well Using Analytical Modeling

Jee-Hun Jeong,Ho-Jun Lee,Ogyun Seok

doi:10.3390/app112412075

Abstract

A new analytical model to analyze and optimize the electrical characteristics of 4H-SiC trench-gate metal-oxide-semiconductor field-effect transistors (TMOSFETs) with a grounded bottom protection p-well (BPW) was proposed. The optimal BPW doping concentration (NBPW) was extracted by analytical modeling and a numerical technology computer-aided design (TCAD) simulation, in order to analyze the breakdown mechanisms for SiC TMOSFETs using BPW, while considering the electric field distribution at the edge of the trench gate. Our results showed that the optimal NBPW obtained by analytical modeling was almost identical to the simulation results. In addition, the reverse transfer capacitance (Cgd) values obtained from the analytical model correspond with the results of the TCAD simulation by approximately 86%; therefore, this model can predict the switching characteristics of the effect BPW regions.

Highlights

Wide energy bandgap materials such as silicon carbide (SiC) and gallium nitride (GaN) are recognized as promising candidates for high-power devices due to a superior inherent property
The reverse transfer capacitance (Cgd ) values obtained from the analytical model correspond with the results of the technology computer-aided design (TCAD) simulation by approximately 86%; this model can predict the switching characteristics of the effect bottom protection p-well (BPW) regions
As the BPW doping concentration (NBPW ) increases, the electric field at the oxide decreases under 4 MV/cm by spreading the trench corner, so that the reliability of the gate oxide can be ensured [13,14]

Summary

Introduction

Wide energy bandgap materials such as silicon carbide (SiC) and gallium nitride (GaN) are recognized as promising candidates for high-power devices due to a superior inherent property. BPW doping concentrations influence the electric field at the gate oxide, the effective thickness of the drift layer, and the parasitic capacitances. As the BPW doping concentration (NBPW ) increases, the electric field at the oxide decreases under 4 MV/cm by spreading the trench corner, so that the reliability of the gate oxide can be ensured [13,14]. This can decrease blocking characteristic because the effective thickness of the drift layer decreases when NBPW exceeds the optimal condition. To set BPW as ground [15,22]

Design of Analytic Method

Results and Discussion

Although the

Conclusions