On-site generation of ultra-high-purity buffered-HF and ammonium fluoride
US6350425B2 · kind B2 · utility
11Cited by
26References
25Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 24, 1997 |
| Grant date | Feb 26, 2002 |
| Priority date | — |
| Expiry date | Jun 24, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/67023
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Provided is a novel method and system for preparing ultra-high-purity buffered-hydrofluoric acid or ammonium fluoride controlled concentration The method comprises bubbling purified ammonia vapor into ultra-pure hydrofluoric acid. The inventive method and system can be used as an on-site subsystem in a semiconductor device fabrication facility for supplying the buffered-hydrofluoric acid and ammonium fluoride to points of use in the semiconductor device fabrication facility.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.