Abstract
Silicon carbide (SiC) power mosfets are promising alternatives to Si devices in high-voltage, high-frequency, and high-temperature applications. The rapid and widespread deployment of SiC devices raises long-term reliability concerns, particularly for mission and safety critical systems due to limited field data and potential uncertainties. Therefore, it is essential to investigate progressive degradations and parameter shifts in SiC devices to develop system integrated degradation monitoring tools for self-monitoring converters, which can recognize failure precursors at the earliest stage and prevent catastrophic failures. This paper presents a comprehensive long-term reliability analysis of commercially available SiC mosfets under high temperature operation and high temperature swing, degradation related key precursors, and possible causes behind them. For this purpose, discrete SiC devices are power cycled and all datasheet parameters are recorded at certain intervals with the aid of the curve tracer. Variation of electrical parameters throughout the tests is presented in order to assess their correlation with the aging/degradation state of the switch. Among them, gate oxide charge trapping related threshold voltage drift and corresponding on state resistance variation has been observed for all samples. For some samples, bond wire heel cracking is found to be the root cause of sudden on state resistance and body diode voltage increases. The discussions regarding aging precursors are supported by failure analysis obtained through the decapsulation of failed devices. Finally, the findings are evaluated in order to define the suitability of electrical parameters as an aging precursor parameter under the light of practical implementation related issues.
| Original language | English |
|---|---|
| Article number | 8603754 |
| Journal | IEEE Transactions on Industry Applications |
| Volume | 55 |
| Issue number | 3 |
| Pages (from-to) | 2858-2867 |
| Number of pages | 10 |
| ISSN | 0093-9994 |
| DOIs | |
| Publication status | Published - 1 May 2019 |
| Externally published | Yes |
Bibliographical note
Funding Information:Manuscript received August 28, 2018; revised November 19, 2018; accepted December 28, 2018. Date of publication January 7, 2019; date of current version April 20, 2019. Paper 2018-IPCC-0882.R1, presented at the 2017 IEEE Energy Conversion Congress and Exposition, Cincinnati, OH, USA, Oct. 1–5, and approved for publication in the IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS by the Industrial Power Converter Committee of the IEEE Industry Applications Society. This work was supported in part by the TXACE/SRC under Task 2712.026 and NSF Grant 1454311. (Corresponding author: Bilal Akin.) E. Ugur, F. Yang, S. Pu, and B. Akin are with the Power Electronics and Drives Laboratory, Department of Electrical and Computer Science, The University of Texas at Dallas, Richardson, TX 75083, USA (e-mail:,enes.ugur@utdallas.edu; fei.yang@utdallas.edu; shi.pu@utdallas.edu; bilal.akin@utdallas.edu).
Publisher Copyright:
© 1972-2012 IEEE.
Keywords
- Accelerated power cycling
- aging assessment
- fault diagnosis
- health monitoring
- power MOSFETs
- reliability
- robustness
- silicon carbide (SiC).