Multi-Step junction termination extension design and simulation study for 4H-SiC Schottky barrier diode

Abstract

This paper presents a structure for designing Junction Termination Extension (JTE) in Silicon Carbide (SiC) power devices, particularly for Schottky Barrier Diodes (SBD). The P-type island composite multi-step JTE configuration has been developed by optimizing the number, length, and thickness of JTE steps. The JTE with step number of 4 and step length of 8 μm (SBD-n4L8) achieved a breakdown voltage of 1626 V at the same drift layer thickness of 10 μm, outperforming other step-based JTE structures. At reverse voltage of 1200 V, the SBD-n4L8 demonstrates a decrease in reverse leakage current with a uniform step-like current distribution profile. Subsequent analysis of the underlying mechanisms showed that, with step thickness of 2 μm, the SBD-n5L8 located at the corner and edge of the terminal region significantly reduced the peak electric field by more than 12.6 %.