Industrial and Body Diode Qualification of Gen-III Medium Voltage SiC MOSFETs: Challenges and Solutions

In this work, we report the results of industrial qualification tests run on medium voltage SiC MOSFETs rated for 3.3 kV/40 A and 10 kV/15 A. The JEDEC JESD47J.01 standard was used as a guideline to conduct HTRB (High Temperature, Reverse Bias), HTGB (High Temperature, Gate Bias), and TDDB (Time Dependent Dielectric Breakdown) tests. No devices were found to have failed the qualification tests, and long oxide lifetime was projected for constant operation under positive bias. This paper also reports for the first time the results of qualification testing of the MOSFET body diode on a large population of medium voltage SiC MOSFETs. Constant current stress at a current equal to the device forward rating was applied for 1000 hours. No degradation of any device parameter was observed for 3 lots of devices at both the 3.3 kV and 10 kV voltage rating.