Termination for trench MIS device
US7795675B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 21, 2005 |
| Grant date | Sep 14, 2010 |
| Priority date | — |
| Expiry date | Sep 21, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D64/516
Abstract
A trench MIS device is formed in a P-epitaxial layer that overlies an N-epitaxial layer and an N+ substrate. In one embodiment, the device includes an N-type drain-drift region that extends from the bottom of the trench to the N-epitaxial layer. Preferably, the drain-drift region is formed at least in part by fabricating spacers on the sidewalls of the trench and implanting an N-type dopant between the sidewall spacers and through the bottom of the trench. The drain-drift region can be doped more heavily than the conventional “drift region” that is formed in an N-epitaxial layer. Thus, the device has a low on-resistance. The device can be terminated by a plurality of polysilicon-filled termination trenches located near the edge of the die, with the polysilicon in each termination trench being connected to the mesa adjacent the termination trench.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.