Metallic interconnect pad, and integrated circuit structure using same, with reduced undercut
US5796168A · kind A · utility
19Cited by
15References
8Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 6, 1996 |
| Grant date | Aug 18, 1998 |
| Priority date | — |
| Expiry date | Sep 6, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/14
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Reduced undercutting of a titanium-tungsten layer in a ball limiting metallurgy (BLM) is achieved in the preparation of solder ball interconnect structures by removing metal oxide film which forms on the titanium-tungsten layer and etching the titanium-tungsten layer in different steps. Removing the metal oxide with an acid solution prior to etching the titanium-tungsten layer provides for a more uniform etch of the titanium-tungsten layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.