Trench-gate transistor with ono gate dielectric and fabrication process therefor
US7354829B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 28, 2004 |
| Grant date | Apr 8, 2008 |
| Priority date | — |
| Expiry date | Jan 25, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D64/681
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A trench-gate type transistor has a gate insulating film formed on an inner wall of a trench. The gate insulating film includes a first portion located on a wall of the trench and a second portion located on upper and bottom portions of the trench. The first portion includes a first oxide film, a nitride film, and a second oxide film. The second portion includes only an oxide film and is thicker than the first portion. Accordingly, electric field concentration on upper and lower corner portions of the trench can be reduced to improve the withstand voltage. In addition, and end of the trench may have an insulation layer that is thicker than the first portion.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.