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Dynamic Degradation in SiC Trench MOSFET With a Floating p-Shield Revealed With Numerical Simulations.
- Source :
-
IEEE Transactions on Electron Devices . Jun2017, Vol. 64 Issue 6, p2592-2598. 7p. - Publication Year :
- 2017
-
Abstract
- A p-type shield region (p-shield) under the gate trench is typically adopted in a SiC trench MOSFET for achieving a lower oxide field and reverse transfer capacitance ( Crss) . This paper comparatively studies the effects of a grounded p-shield and a floating p-shield. Device simulations using Sentaurus TCAD are carried out in this paper to reveal the devices’ internal dynamics. The floating p-shield can effectively reduce the OFF-state oxide field as a grounded p-shield does, without degrading its static performance. However, after being switched from the OFF-state, the ON-state oxide field in the trench MOSFET with a floating p-shield (FS-MOS) is dramatically elevated. Compared with the trench MOSFET with a grounded p-shield, the FS-MOS also exhibits a higher C{{\text {rss}}} and a consequently slower switching speed. Furthermore, the FS-MOS exhibits a degradation of dynamic R{ \mathrm{ON}} during switching operation. A charge storage mechanism is then presented to explain the dynamics in FS-MOS. Upon a high V{{\text {DS}}} , holes are emitted from the floating p-shield when the parasitic p-n-p structure consisting of p-shield, p-body, and n-region between them is punched through, leaving negative charges in the floating p-shield even when the high V{{\text {DS}}} is removed. Based on this mechanism, the behaviors of the FS-MOS are well explained. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00189383
- Volume :
- 64
- Issue :
- 6
- Database :
- Academic Search Index
- Journal :
- IEEE Transactions on Electron Devices
- Publication Type :
- Academic Journal
- Accession number :
- 124146847
- Full Text :
- https://doi.org/10.1109/TED.2017.2697763