Mechanisms for forming copper pillar bumps
US8659155B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 29, 2010 |
| Grant date | Feb 25, 2014 |
| Priority date | — |
| Expiry date | Jun 26, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/3651
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
The mechanism of forming a metal bump structure described above resolves the delamination issues between a conductive layer on a substrate and a metal bump connected to the conductive layer. The conductive layer can be a metal pad, a post passivation interconnect (PPI) layer, or a top metal layer. By performing an in-situ deposition of a protective conductive layer over the conductive layer (or base conductive layer), the under bump metallurgy (UBM) layer of the metal bump adheres better to the conductive layer and reduces the occurrence of interfacial delamination. In some embodiments, a copper diffusion barrier sub-layer in the UBM layer can be removed. In some other embodiments, the UBM layer is not needed if the metal bump is deposited by a non-plating process and the metal bump is not made of copper.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.