Liquid etchant composition for thin film resistor element
US5256247A · kind A · utility
20Cited by
6References
5Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 21, 1991 |
| Grant date | Oct 26, 1993 |
| Priority date | — |
| Expiry date | Nov 21, 2011 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B2111/00844
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A resistor material having at least chromium, silicon and oxygen, Cr.SiO.sub.2, contained in electronic integrated circuits, particularly in the case of an aluminum layer being on the material, is etched with a liquid etchant composition containing 1.92 to 2.64 mol/l of hydrochloric acid, 0.26 to 0.77 mol/l of phosphoric acid, 5 to 10 mol/l hydrofluoric acid and 3.2 to 5.4 mol/l of ammonium fluoride.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.