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

碳化硅（SiC）单极器件，如MOSFET和肖特基二极管，预计将成为未来转换器的首选半导体。基于单极SiC器件的自补偿电压源换流器（VSC）有望通过缩小换流器（无源元件）的尺寸、提高能量转换效率和简化冷却系统来彻底改变并网电力电子设备。这种新材料在以硅为主的行业中的可靠性仍然相对未知，如果要在SiC中建立信心，则需要针对器件和转换器进行基于物理的精确可靠性预测和设计工具。此外，需要更先进的栅极驱动器和状态监控系统来充分发挥碳化硅的优势。在寄生电感存在的情况下，快速开关器件将受到相当大的介电应力和电磁应力。电力电子模块由具有不同热膨胀系数的材料组成，因此，由于重复的电气开关，在关键界面处发生裂纹生长和传播。这种机械损伤/疲劳改变了器械的抗疲劳性能。由于电-热-机械应力引起的热失控是对能量密集SiC器件的长期可靠性的重大威胁，特别是因为与器件技术相比，封装技术的进步滞后。该博士学位的目的是设计和开发新的栅极驱动和状态监测系统，以改善SiC功率器件的运行。

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.