Short-Circuit Capability Prediction and Failure Mode of Asymmetric and Double Trench SiC MOSFETs
Short-Circuit Capability Prediction and Failure Mode of Asymmetric and Double Trench SiC MOSFETs
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DOI：
10.1109/tpel.2020.3047896
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发表时间：
2021-07-01
影响因子：
6.7
通讯作者：
Zhang, Bo
中科院分区：
文献类型：
--
作者：
Deng, Xiaochuan;Li, Xu;Zhang, Bo
本文提出了1200 V级双非对称沟槽结构SiC MOSFET在单脉冲短路应力下的短路能力预测和失效模式。建立了短路预测模型，用于评估不同直流母线电压下器件的短路耐受时间和相应的临界能量。该模型在试验结果较少的情况下也能提供快速的预测指导，且预测值与实际值一致。此外，两个故障模式进行了研究，在短路试验。对于非对称沟槽SiC MOSFET，故障模式是栅极损坏在较低的直流总线电压和热失控在较高的直流总线电压，而双沟槽SiC MOSFET的故障模式是热失控在所有直流总线电压。此外，内部的热-电应力的装置进行了分析，直到它在短路条件下失效，并证明了故障模式取决于直流母线电压和峰值短路电流的装置。最后，通过对失效器件的俯视图分析，证实了沟槽SiC MOSFET的两种失效模式。
In this article, short-circuit capability prediction and failure mode of 1200-V-class SiC MOSFETs with a double and asymmetric trench structure are proposed under single-pulse short-circuit stress. A short-circuit prediction model is established to evaluate short-circuit withstand time and corresponding critical energy of devices under various dc bus voltages. This model can provide quick predictive guidance even if there are few test results, and the predicted values are consistent with practical values. Furthermore, two failure modes are investigated in a short-circuit test. For asymmetric trench SiC MOSFETs, failure modes are gate damage at lower dc bus voltages and thermal runaway at higher dc bus voltages; whereas failure mode for double trench SiC MOSFETs is thermal runaway at all dc bus voltages. In addition, the internal thermal-electro stress of the device is analyzed until it fails during short-circuit condition, and proves that failure mode depends on the dc bus voltage and peak short-circuit current of the device. Finally, the top view of failed devices confirms the two failure modes of trench SiC MOSFETs by the postdecapsulation.