Etchant solution containing HF-HnO.sub.3 -H.sub.2 SO.sub.4 -H.sub.2 O.sub.2
US4220706A · kind A · utility
41Cited by
13References
5Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | May 10, 1978 |
| Grant date | Sep 2, 1980 |
| Priority date | — |
| Expiry date | May 10, 1998 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/28
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
An etchant solution for multilayered metal layers comprising an aqueous solution of from 0.5 to 50 percent by weight of nitric acid, from 0.03 to 1.0 percent by weight of hydrofluoric acid, from 0.05 to 0.5 percent by weight of hydrogen peroxide and from 0.1 to 1.0 percent by weight of sulphuric acid. The solution is compatible with photolithographic techniques and uniformly etches three or more metals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.