Method of etching copper layers
US5409567A · kind A · utility
8Cited by
2References
16Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 28, 1994 |
| Grant date | Apr 25, 1995 |
| Priority date | — |
| Expiry date | Apr 28, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K2201/0317
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method for etching a composite copper layer (40) of plated copper (20) overlying physical vapor deposited copper (30) comprises etching the plated copper (20) at a rate less than the rate of etch of the physical vapor deposited copper (30). The etching may be accomplished with an aqueous solution of ammonium peroxydisulfate with molar concentrations of ammonium ions between 0.0438 and 0.1052, at a temperature between 30.degree. and 35.degree. C. and with the pH buffered to remain at a value between 1 and 1.8.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.