Study on short-circuit characteristics of semi-super-junction SiC MOSFETs

In this paper, the short-circuit (SC) characteristics of conventional and semi-super-junction (semi-sj) SiC MOSFETs are investigated using 2D numerical simulation, revealing a possible short-circuit failure mechanism and performance degradation mechanism of SiC MOSFET. Comparing the short-circuit characteristics of the two devices, it is found that the semi-sj SiC MOSFET exhibits superior short-circuit characteristics and relatively weak performance degradation due to the introduction of the P-pillar region. Meanwhile, combined with the static characterization of the devices, it is found that the semi-sj SiC MOSFET has better overall performance. In addition, the short-circuit reliability of semi-sj SiC MOSFETs can be further optimized concerning device structural parameters such as the thickness and doping concentration of the N-type bottom auxiliary layer and the thickness of the gate oxide layer.