Method for purifying nitrogen trifluoride gas
US5183647A · kind A · utility
11Cited by
9References
14Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 28, 1991 |
| Grant date | Feb 2, 1993 |
| Priority date | — |
| Expiry date | May 28, 2011 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01B21/0832
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
NF.sub.3 gas containing N.sub.2 F.sub.2 as an impurity is purified by heating said NF.sub.3 gas at specified temperatures in a vessel the inner wall of which is coated with a strong and passive film of nickel flouride. According to this method, the rate of NF.sub.3 loss is low and the rate of removing N.sub.2 F.sub.2 is high. Therefore, when the NF.sub.3 gas thus purified is further purified with a known adsorbent, a highly pure NF.sub.3 gas can be easily and safely produced which is suitable for materials for semiconductor dry etching agents and the like.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.