Dry-etching gas for semiconductor process and preparation method thereof
US7319174B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 25, 2006 |
| Grant date | Jan 15, 2008 |
| Priority date | — |
| Expiry date | Sep 25, 2026 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C23/08
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The invention is a method for continuously preparing highly pure octafluorocyclopentene for use in dry-etching processes. The method includes reacting octachlorocyclopentene with KF in a continuous manner, and purifying crude octafluorocyclopentene. In the reacting step, two KF-charged filters are installed in parallel and allowed to communicate with a reactor containing octachlorocyclopentene in an alternating manner to produce crude octafluorocyclopentene. In the purifying step, organics having lower boiling points than octafluorocyclopentene are removed, and metal ingredients and organics having boiling points higher than octafluorocyclopentene are separated to recover octafluorocyclopentene as a gas. The gaseous octafluorocyclopentene composition contains C5F8 in an amount of 99.995 vol % or higher, nitrogen in an amount of 50 vol ppm or less, oxygen in an amount of 5 vol ppm or less, water in an amount of 5 vol ppm or less, and metal ingredients in an amount of 5 wt ppb or less.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.