Edge termination in MOS transistors
US6936890B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 6, 2002 |
| Grant date | Aug 30, 2005 |
| Priority date | — |
| Expiry date | Dec 29, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D64/513
Abstract
A RESURF trench gate MOSFET has a sufficiently small pitch (close spacing of neighbouring trenches) that intermediate areas of the drain drift region are depleted in the blocking condition of the MOSFET. However, premature breakdown can still occur in this known device structure at the perimeter/edge of the active device area and/or adjacent the gate bondpad. To counter premature breakdown, the invention adopts two principles: These principles can be implemented in various cellular layouts e.g. a concentric annular device geometry, which may be circular or rectangular or ellipsoidal, in the active area and in the edge termination, or a device array of such concentric hexagonal or circular stripe cells, or a device array of square active cells with stripe edge cells, or a device array of hexagonal active cells with an edge termination of hexagonal edge cells.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.