Online Threshold Voltage Monitoring at SiC Power Devices during Power Cycling Test and Possible Consequences

In this paper, the threshold voltage shift during power cycling test for discrete SiC-MOSFET devices in TO-247 package from three different manufacturers with the same blocking capability of 1200 V is investigated. The temperature dependence of the threshold voltage plays a significant role in the interpretation of the results, since a change in V
th
can also influence common TSEP (temperature-sensitive electrical parameter) measurement methods. The tested devices have shown no deterioration of the solder layer, but degradation of the bond wires in the failure analysis.