Reliability Aspects Of 1200v And 3300v Silicon Carbide Mosfets

We have demonstrated 1200V and 3300V planar 4H-SiC MOSFET technology at our 6-inch foundry. 1200V MOSFETs demonstrate good avalanche ruggedness under single and one million (1,000,000) repetitive unclamped inductive switching (UIS) pulse tests. 1200V MOSFETs can pass one hundred (100) 10 microsecond short-circuit events at 600V bus voltage, while 3300V MOSFETs can pass 5 microsecond short-circuit event at 2200V bus voltage. Both UIS and short-circuit events induce a positive threshold voltage shift, with a significant portion of it being reversible and likely being caused by electron trapping. Exposure of the MOSFET's built-in body diode to 3-rd quadrant pulsed surge current causes expansion of basal plane dislocations in 3300V MOSFETs, severely affecting device static characteristics. At the same time, no degradation is observed in 1200V MOSFETs under the same repeated pulsed surge current test conditions.