Multi-film stack etching with polymer passivation of an overlying etched layer
US8747684B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 20, 2010 |
| Grant date | Jun 10, 2014 |
| Priority date | — |
| Expiry date | Sep 26, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D88/00
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for plasma etching a workpiece, such as a semiconductor wafer, including a thin film stack having a top film disposed over a bottom film with an intervening middle film there between. Etch selectivity between the top and bottom films may be as low as between 1:1 and 2:1 and a first carbon-lean gas chemistry is used to etch through the top film, a second carbon-lean gas chemistry is used to etch through the middle film, and the bottom film is etched through by alternating between depositing a polymer passivation on the top film using a carbon-rich gas chemistry and an etching of the bottom film with a third carbon-lean gas chemistry, which may be the same as the first carbon-lean gas chemistry.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.