Method of plasma etching a deeply recessed feature in a substrate using a plasma source gas modulated etchant system
US7074723B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 2, 2002 |
| Grant date | Jul 11, 2006 |
| Priority date | — |
| Expiry date | Mar 12, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/30655
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
We have developed an uncomplicated method of plasma etching deeply recessed features such as deep trenches, of at least 5 μm in depth, in a silicon-containing substrate, in a manner which generates smooth sidewalls, having a roughness of less than about 1 μm, typically less than about 500 nm, and even more typically between about 100 nm and 20 nm. Features having a sidewall taper angle, relative to an underlying substrate, typically ranges from about 85° to about 92° and exhibiting the smooth sidewalls are produced by the method. In one embodiment, a stabilizing etchant species is used constantly during the plasma etch process, while at least one other etchant species and at least one polymer depositing species are applied intermittently, typically periodically, relative to each other. In another embodiment, the stabilizing etchant species is used constantly and a mixture of the other etchant species and polymer depositing species is used intermittently.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.