Low voltage high density trench-gated power device with uniformly doped channel and its edge termination technique
US6784505B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | May 3, 2002 |
| Grant date | Aug 31, 2004 |
| Priority date | — |
| Expiry date | May 3, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D62/151
Abstract
Merging together the drift regions in a low-power trench MOSFET device via a dopant implant through the bottom of the trench permits use of a very small cell pitch, resulting in a very high channel density and a uniformly doped channel and a consequent significant reduction in the channel resistance. By properly choosing the implant dose and the annealing parameters of the drift region, the channel length of the device can be closely controlled, and the channel doping may be made highly uniform. In comparison with a conventional device, the threshold voltage is reduced, the channel resistance is lowered, and the drift region on-resistance is also lowered. Implementing the merged drift regions requires incorporation of a new edge termination design, so that the PN junction formed by the P epi-layer and the N+ substrate can be terminated at the edge of the die.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.