Self-aligned last-metal C4 interconnection layer for Cu technologies
US6426557B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 25, 2000 |
| Grant date | Jul 30, 2002 |
| Priority date | — |
| Expiry date | Feb 25, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/14
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A controlled collapse chip connection (C4) structure having stronger resistance to failure is constructed for use with integrated circuit devices having copper wiring. Failure resistance is obtained by replacing the mechanically weak final passivation to copper interface. The weak interface is eliminated by use of a specific peg on peg structure together with a layer of shunt metal having excellent adhesion and barrier characteristics. A shunt metal, e.g., Ta or TaN, is placed between both the copper and final passivation and the copper and C4 metals such that it overlaps the edge of the peg defined wiring mesh to encase the copper. Overlap is obtained by the peg on peg structure where a SiO2 peg defines the copper wire mesh and a smaller Si3N4 peg placed on the SiO2 peg defines the overlap above the mesh wire and provides the ability to pattern the overlayer shunt without exposure of the copper conductor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.