Termination for trench MIS device having implanted drain-drift region
US7045857B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 26, 2004 |
| Grant date | May 16, 2006 |
| Priority date | — |
| Expiry date | Apr 10, 2024 |
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. The polysilicon material in each termination trenches.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.