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.

The widespread adoption of energy storage deployment requires the cost for the power conversion stages to be significantly reduced. The high cost of inversion is driven largely by the performance limitations of Si-IGBTs and SiIGCTs, especially when a higher DC-link voltage (>1 kV) is desired to facilitate the reduction of the balance-of-system. SiC unipolar devices, however, offer great promise for increasing the DC link voltage, while maintaining high system efficiency without increasing system complexity. Such a switch platform could enable small, lightweight, transformerless topologies for industrial medium voltage grid applications operating at 3.3 or 4.16 kV AC. This report discusses the state-of-the-art 1.2kV SiC JFETs as a proven technology platform, and demonstrates the benefits of the JFET through operational comparisons with SiC-MOSFETs and Si-IGBTs. In addition, SiC JFET device reliability is demonstrated up to 200°C and the impact of a 6.5 kV JFET platform on power conversion systems is discussed.