Power MOSFET with recessed field plate
US7843004B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 25, 2007 |
| Grant date | Nov 30, 2010 |
| Priority date | — |
| Expiry date | Oct 17, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D64/516
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A trench MOSFET contains a recessed field plate (RFP) trench adjacent the gate trench. The RFP trench contains an RFP electrode insulated from the die by a dielectric layer along the walls of the RFP trench. The gate trench has a thick bottom oxide layer, and the gate and RFP trenches are preferably formed in the same processing step and are of substantially the same depth. When the MOSFET operates in the third quadrant (with the source/body-to-drain junction forward-biased), the combined effect of the RFP and gate electrodes significantly reduces in the minority carrier diffusion current and reverse-recovery charge. The RFP electrode also functions as a recessed field plates to reduce the electric field in the channel regions when the MOSFET source/body to-drain junction reverse-biased.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.