Eliminating antiparallel silicon carbide Schottky barrier diode (SiC SBD) and making use of the intrinsic body diode of SiC metal-oxide-semiconductor-field-effect transistor (SiC MOSFET) offer a cost-effectiveness solution without obviously sacrificing the conversion efficiency in some power converter applications. Although the body diode of commercial SiC MOSFET has been qualified by several manufacturers, the reliability of SiC MOSFET under repetitive surge current stress of body diode has not been sufficiently studied. In this article, the new degradation phenomena of SiC MOSFET's gate oxide are observed, and the degradation mechanism is discussed when the intrinsic body diode of the 1200-V SiC planar gate MOSFETs was subjected to surge current stress. TCAD simulation and experimental measurements indicate that the generation and accumulation of electrons or holes within the gate oxide under surge current stress are the main reasons for the degradation of SiC MOSFET. Finally, a mitigation technique with optimal gate turn-off voltage is suggested to suppress the gate oxide degradation of the SiC MOSFET under surge current stress of its body diode.

中文翻译：

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体二极管的浪涌电流应力下SiC MOSFET的退化研究

消除反并联碳化硅肖特基势垒二极管（SiC SBD），并利用SiC金属氧化物半导体场效应晶体管（SiC MOSFET）的本征二极管，可以提供一种成本有效的解决方案，而不会明显牺牲某些电源的转换效率转换器应用。尽管商用SiC MOSFET的体二极管已经通过了多家制造商的认证，但是对于体二极管的重复浪涌电流应力，SiC MOSFET的可靠性还没有得到足够的研究。在本文中，观察了SiC MOSFET栅极氧化物的新的退化现象，并讨论了1200-V SiC平面栅极MOSFET的本征二极管承受浪涌电流应力时的退化机理。TCAD仿真和实验测量表明，在浪涌电流应力下，栅极氧化物内电子或空穴的产生和积累是SiC MOSFET退化的主要原因。最后，建议采用具有最佳栅极关断电压的缓解技术来抑制SiC MOSFET在其体二极管的浪涌电流应力下的栅极氧化物退化。