Study of short-circuit robustness of SiC MOSFETs, analysis of the failure modes and comparison with BJTs

• Published in: Microelectronics and reliability Vol. 55; no. 9-10; pp. 1708 - 1713
• Main Authors: Chen, Cheng, Labrousse, Denis, Lefebvre, Stéphane, Petit, Mickael, Buttay, Cyril, Morel, Hervé
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.08.2015; Elsevier
• Subjects: BJT; Engineering Sciences; MOSFET; Short circuit; SiC; MOSFET; Short circuit; SiC; BJT; short circuit
• ISSN: 0026-2714; 1872-941X
• DOI: 10.1016/j.microrel.2015.06.097

This paper presents experimental robustness tests made on Silicon Carbide (SiC) MOSFETs and SiC Bipolar Junction Transistors (BJTs) submitted to short-circuit operations (SC) or current limitation modes. For SiC MOSFETs, a gate leakage current is detected before failure without being responsible for the immediate failure. Nevertheless this gate leakage current is not without effect on the integrity of the SiC MOSFETs. Based on several robustness tests performed on SiC MOSFETs and on the comparison with experimental results obtained with SiC BJTs, the paper points out two main failure modes for SiC MOSFETs. The first one results in a simultaneously short circuit between drain and gate and drain and source and the second one in a degradation of the insulation between gate and source leading to a short circuit between gate and source. For some tested devices, the failure appears in a very interesting open state mode between drain and source after physical short-circuit between gate and source with a mode of failure very similar to those observed for SiC BJT. •SiC MOSFETs and BJTs will be tested in short-circuit or current limitation modes.•Safe failure appears for some SiC MOSFETs and BJTs in short-circuit operations.•For SiC MOSFETs, a gate leakage current and two main failure modes are detected.•Gate leakage current does not result in the failure in one-time short circuit test.•Gate leakage current will limit MOSFETs' robustness in repetitive short circuit mode.