Method for forming semiconductor contacts by electroless plating
US5075259A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 22, 1989 |
| Grant date | Dec 24, 1991 |
| Priority date | — |
| Expiry date | Aug 22, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/288
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Semiconductor device structures having very smooth surfaces and very high doping levels of opposite types present on the same wafer may be plated in the same electroless plating bath without differentiation between the N and P regions or rough and smooth surface regions. This is achieved by a pre-treatment involving coating the wafer surface with a metal salt (e.g., NiCl in glycol and water) and reducing the metal salt in an oxygen free atmosphere (e.g., hydrogen) at a temperature (e.g., >300.degree. C. for Si) sufficient to promote formation of an intermetallic between the reduced metal and the semiconductor substrate. This provides very uniform and effective nucleation sites for the subsequent electroless plating process irrespective of the smoothness, doping type and doping density of the semiconductor surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.