Method for manufacturing a semiconductor device having a trench and a thick insulation film at the trench opening
US6797588B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 29, 2002 |
| Grant date | Sep 28, 2004 |
| Priority date | — |
| Expiry date | Mar 29, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D64/681
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A surface of a semiconductor substrate is selectively etched to form a first opening, which serves as the opening of a trench. A USG film is deposited on the first opening. A second opening, the width of which is smaller than that of the first opening, is formed in the USG film within the first opening. An inner section of the trench is formed by etching while using the USG film as a mask. The inner surface of the inner region is thermally oxidized to form a silicon oxide film, and a gate insulating film is made by the silicon oxide film and the USG film. A gate electrode is formed in the trench. The gate insulating film is relatively thick at the opening of the trench, so the breakdown voltage at the opening of the trench is increased.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.