Measurements and Review of Failure Mechanisms and Reliability Constraints of 4H-SiC Power MOSFETs Under Short Circuit Events

Abstract

The reliability of the SiC MOSFET has always been a factor hindering the device application, especially under high voltage and high current conditions, such as in the short circuit events. This paper experimentally reviews the failure mechanisms caused by destructive short circuit impulses, and investigates the degradation patterns of key electrical parameters under repetitive short circuit events. The impact of test parameters on the short circuit reliability of SiC MOSFET has been analyzed. Approaches to characterize the electrical-thermal-mechanical stress during the short circuit period and advanced test methods are highlighted. Finally, the constraints from the standpoint of both manufacturers and users have been presented, including comparison of current SiC MOSFET devices, reliability evaluation of parallel SiC MOSFET devices, reliability improvement of the chip, performance improvement of protection circuits, and reliability assessment of SiC MOSFET devices under application-representative stress.