Electroplating solution for forming Pb-Sn alloy bump electrodes on semiconductor wafer surface
US5651873A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jun 26, 1995 |
| Grant date | Jul 29, 1997 |
| Priority date | — |
| Expiry date | Jun 26, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/15747
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
An electroplating solution (A), comprises an aqueous solution consisting essentially of lead phenolsulfonate: 1 to 250 g/liter in terms of Pb content; tin phenolsulfonate: 0.1 to 250 g/liter in terms of Sn content; phenolsulfonic acid: 20 to 300 g/liter; polyoxyethylene polyoxypropylene alkylamine: 1 to 50 g/liter; a 1-naphthaldehyde derivative: 0.001 to 1 g/liter; and an aldol sulfanilic acid derivative: 0.1 to 30 g/liter; or an aqueous solution (B) consisting essentially of lead methanesulfonate: 1 to 250 g/liter in terms of Pb content; tin methanesulfonate: 0.1 to 250 g/liter in terms of Sn content; methanesulfonic acid: 20 to 300 g/liter; polyoxyethylene polyoxypropylene alkylamine: 1 to 50 g/liter; and an aldol sulfanilic acid derivative: 0.1 to 30 g/liter. Each of the electroplating aqueous solutions (A) and (B) contains 50 ppb or less radioactive isotopes, whereby Pb-Sn alloy bump electrodes with improved uniformity in height and improved surface smoothness can be formed on a surface of a semiconductor wafer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.