High purity phosphoric acid and process of producing the same
US7470414B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 28, 2004 |
| Grant date | Dec 30, 2008 |
| Priority date | — |
| Expiry date | Oct 26, 2025 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01B25/234
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
High purity phosphoric acid having an Sb content of 200 ppb or less and a sulfide ion content of 200 ppb or less as impurity contents on a 85 weight percent H3PO4 basis. The high purity phosphoric acid is useful as an etching solution for semiconductor devices having a silicon nitride film, an etching solution for liquid crystal display panels having an alumina film, a metallic aluminum etching solution, an alumina etching solution for ceramics, a raw material of phosphate glass for optical fiber, a food additive, and so forth. A metallic material having low capability of forming a lithium compound penetrates through the whole thickness of the active material layer 5.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.