# Novel 4H-SiC Double-Trench MOSFETs with Integrated Schottky Barrier and MOS-Channel Diodes for Enhanced Breakdown Voltage and Switching Characteristics

## TL;DR

This paper introduces a new SiC double-trench MOSFET design that improves breakdown voltage and switching performance by integrating Schottky and MOS-channel diodes.

## Contribution

The novel integration of SBD and MCD in a SiC double-trench MOSFET enhances device performance by reducing bipolar degradation and improving switching characteristics.

## Key findings

- Breakdown voltage improved from 800 V to 1069 V through Schottky contact adjustment.
- Turn-on switching rise time decreased from 2.58 ns to 0.68 ns due to reduced gate-to-drain capacitance.
- Reverse conduction is less affected by source oxide thickness with optimized SBD positioning.

## Abstract

In this study, a novel silicon carbide (SiC) double-trench MOSFET (DT-MOS) combined Schottky barrier diode (SBD) and MOS-channel diode (MCD) is proposed and investigated using TCAD simulations. The integrated MCD helps inactivate the parasitic body diode when the device is utilized as a freewheeling diode, eliminating bipolar degradation. The adjustment of SBD position provides an alternative path for reverse conduction and mitigates the electric field distribution near the bottom source trench region. As a result of the Schottky contact adjustment, the reverse conduction characteristics are less influenced by the source oxide thickness, and the breakdown voltage (BV) is largely improved from 800 V to 1069 V. The gate-to-drain capacitance is much lower due to the removal of the bottom oxide, bringing an improvement to the turn-on switching rise time from 2.58 ns to 0.68 ns. These optimized performances indicate the proposed structure with both SBD and MCD has advantages in switching and breakdown characteristics.