Trench etch with incremental oxygen flow
US6680232B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 19, 2001 |
| Grant date | Jan 20, 2004 |
| Priority date | — |
| Expiry date | Dec 30, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/978
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method for forming trenches in a device layer disposed on a silicon semiconductor substrate comprises: covering the device layer with an etch resistant masking layer to define at least two trench regions; removing semiconductor material from the exposed trench regions by applying an etching agent that selectively etches the semiconductor substrate with respect to the trench masking layer, thereby forming at least two trenches each comprising a floor and sidewalls; and, during the removal of semiconductor material, exposing the sidewalls to a passivating agent in increasing amounts, thereby passivating the sidewalls while reducing lateral etching of semiconductor material from them.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.