Method of treating waste gases containing halogen compounds
US5322674A · kind A · utility
Assignees
Inventor
Key dates
| Filing date | Dec 21, 1992 |
| Grant date | Jun 21, 1994 |
| Priority date | — |
| Expiry date | Dec 21, 2012 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D53/70
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Halogen-containing waste gases resulting from the dry etching step of the process of fabricating semiconductor devices are rendered harmless by removing the halogen compounds concomitant with said waste gases. Waste gases containing halogen compounds are treated by bringing them into contact first with activated carbon and then into contact with a member selected from the group consisting of an alkali agent and a ferric oxide, at a linear velocity of about 3-50 cm/min at ambient temperature, volume ratios of said activated carbon to the alkali agent or the ferric oxide in terms of a substantially dried base being about 2-4, and said alkali agent being selected from a group consisting of calcium hydroxide, calcium oxide, magnesium hydroxide and magnesium oxide.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.