Advanced Gate Driving for Wide Bandgap Devices - 1=Energy 2=Microelectronic device technology

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Silicon carbide (SiC) unipolar devices like MOSFETs and Schottky diodes are projected to be the semiconductors of choice for future converters. Self-commutating voltage source converters (VSCs) based on unipolar SiC devices promise to revolutionize grid-connected power electronics by shrinking the size of converters, the passive components, improving the efficiency of energy conversion and simplifying cooling systems. The reliability of the this new material in a silicon dominated industry remains relatively unknown and if confidence is to be established in SiC, accurate physics-based reliability prediction and design tools are required for devices and converters. Also, more advanced gate drivers and condition monitoring systems are needed to fully expedite the advantages of silicon carbide. Fast switching devices in the presence of parasitic inductances will be subjected to considerable electrothermal and electromagnetic stresses. Power electronic modules are comprised of materials with different coefficients of thermal expansion hence, crack growth and propagation at critical interfaces occurs as a result of repeated electrical switching. This mechanical damage/fatigue alters the electrothermal performance of the device. Thermal runaway due to electro-thermo-mechanical stresses is a significant threat to the long term reliability of energy dense SiC devices especially since advances in packaging technologies are lagging in comparison to device technology. The purpose of this PhD is to design and develop new gate driving and condition monitoring systems for improving the operation of SiC power devices.