Short Circuit Ruggedness of New Generation 1.2 kV SiC MOSFETs
Short Circuit Ruggedness of New Generation 1.2 kV SiC MOSFETs
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新一代 1.2 kV SiC MOSFET 的短路耐受性
DOI：
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发表时间：
2018
期刊：
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通讯作者：
U. Grossner
中科院分区：
文献类型：
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作者：
Bhagyalakshmi Kakarla;T. Ziemann;R. Stark;P. Natzke;U. Grossner
新一代基于碳化硅 (SiC) 的 MOSFET 已由制造商推出，具有更小的芯片尺寸和更高的功率密度，与上一代同类产品相比，性能有所提高。由于芯片尺寸较小，在类似短路 (SC) 的情况下可用于耗散能量的体积会减小，从而导致器件的自发热增加。因此，短路耐受时间（SCWT）减少。作为可靠性方面，需要分析这些器件对 SC 等极端工作条件的耐用性，以改进设计或在这些 MOSFET 用于特定 SC 易受攻击的应用时为这些 MOSFET 设计更好的检测和保护电路。在这项工作中，测量了 Wolfspeed 采用 TO-247-4 引脚封装且芯片尺寸更小的新型第三代 1.2 kV SiC MOSFET 的 SC 耐用性。基于所进行的破坏性 SC 测试，分析了不同直流母线电压、栅极偏置电压、SC 脉冲持续时间和自热行为下器件失效的原因。经测量，该器件在 800 V 直流母线电压下的 SCWT 为 2 µs，而具有更大芯片尺寸和 TO-247-3 引脚封装的第二代 1.2 kV 器件的 SCWT 为 4.5 µs。与没有开尔文源的相同器件相比，开尔文源触点的存在表现出更高的峰值 SC 电流。
New generations of silicon carbide (SiC) based MOSFETs are commercially available from manufacturers featuring smaller chip size with higher power density demonstrating performance improvement compared to their previous generation counterparts. As the size of the chip is small, the volume available to dissipate energy during short-circuit (SC) like conditions is reduced, leading to increased self-heating of the device. Therefore, the short circuit withstand time (SCWT) is reduced. As a reliability aspect, ruggedness to extreme operating conditions like SC needs to be analyzed for these devices, to improve the design or to design better detection and protection circuits for these MOSFETs when used in specific SC vulnerable applications. In this work, the new third generation 1.2 kV SiC MOSFET from Wolfspeed in a TO-247-4 pin package having a smaller chip size is measured for SC ruggedness. The causes for device failure under different DC-link voltages, gate bias voltages, SC pulse durations and self-heating behavior are analyzed based on the destructive SC tests performed. The device is measured to have an SCWT of 2 µs at a DC-link voltage of 800 V compared to SCWT of 4.5 µsfor the second generation 1.2 kV devices with larger chip size and TO-247-3 pin package. The presence of the Kelvin source contact demonstrates higher peak SC currents compared to the same devices without Kelvin source.