A New High Voltage 4H-SiC Lateral Dual Sidewall Schottky (LDSS) Rectifier: Theoretical Investigation and Analysis

TL;DR

This paper introduces a novel 4H-SiC LDSS rectifier with enhanced performance, demonstrating superior on/off ratio and sharp breakdown characteristics through detailed simulation analysis compared to existing Schottky rectifiers.

Contribution

The paper presents the design and simulation-based analysis of a new 4H-SiC LDSS rectifier, showcasing its dual barrier operation and improved electrical characteristics.

Findings

High on/off current ratio of 5.5x10^7 at 1 V / -500 V

Exhibits sharp breakdown similar to PiN diodes

Acts as low-barrier under forward bias and high-barrier under reverse bias

Abstract

In this paper, we report a new 4H-SiC Lateral Dual Sidewall Schottky (LDSS) rectifier on a highly doped drift layer consisting of a high-barrier sidewall Schottky contact on top of the low-barrier Schottky contact. Using two-dimensional device simulation, the performance of the proposed device has been evaluated in detail by comparing its characteristics with those of the compatible Lateral Conventional Schottky (LCS) and Lateral Trench Sidewall Schottky (LTSS) rectifiers on 4H-SiC. From our simulation results, it is observed that the proposed LDSS rectifier acts as a low-barrier LTSS rectifier under forward bias conditions and as a high-barrier LTSS rectifier under reverse bias conditions making it an ideal rectifier. The LDSS rectifier exhibits an on/off current ratio (at 1 V / -500 V) of 5.5x10e7 for an epitaxial layer doping of 1x10e17 /cm^3. Further, the proposed LDSS structure exhibits a very sharp breakdown similar to that of a PiN diode in spite of using only Schottky junctions in the structure. We have analyzed the reasons for the improved performance of the LDSS.