Affiliation:
1. Department of Electrical & Computer Engineering, The Ohio State University, Columbus, OH 43210, USA
2. Ford Motor Co., Dearborn, MI 48124, USA
Abstract
The body diode degradation in SiC power MOSFETs has been demonstrated to be caused by basal plane dislocation (BPD)-induced stacking faults (SFs) in the drift region. To enhance the reliability of the body diode, many process and structural improvements have been proposed to eliminate BPDs in the drift region, ensuring that commercial SiC wafers for 1.2 kV devices are of high quality. Thus, investigating the body diode reliability in commercial planar and trench SiC power MOSFETs made from SiC wafers with similar quality has attracted attention in the industry. In this work, current stress is applied on the body diodes of 1.2 kV commercial planar and trench SiC power MOSFETs under the off-state. The results show that the body diodes of planar and trench devices with a shallow P+ depth are highly reliable, while those of the trench devices with the deep P+ implantation exhibit significant degradation. In conclusion, the body diode degradation in trench devices is mainly influenced by P+ implantation-induced BPDs. Therefore, a trade-off design by controlling the implantation depth/dose and maximizing the device performance is crucial. Moreover, the deep JFET design is confirmed to further improve the body diode reliability in planar devices.
Subject
Electrical and Electronic Engineering,Mechanical Engineering,Control and Systems Engineering
Reference42 articles.
1. Choi, H. (2016). Overview of Silicon Carbide Power Devices, Fairchild Semiconductor.
2. Siemieniec, R., Peters, D., Esteve, R., Bergner, W., Kück, D., Aichinger, T., Basler, T., and Zippelius, B. (2017, January 11–14). A SiC Trench MOSFET concept offering improved channel mobility and high reliability. Proceedings of the 2017 19th European Conference on Power Electronics and Applications (EPE’17 ECCE Europe), Warsaw, Poland.
3. Relationship Between the 4H-SiC/SiO2 Interface Structure and Electronic Properties Explored by Electrically Detected Magnetic Resonance;Anders;IEEE Trans. Electron Devices,2015
4. Ultrahigh-temperature oxidation of 4H-SiC (0 0 0 1) and gate oxide reliability dependence on oxidation temperature;Wan;J. Cryst. Growth,2020
5. Defect Inspection Techniques in SiC;Chen;Nanoscale Res. Lett.,2022