Under bump metallization structure
US6770958B2 · kind B2 · utility
67Cited by
19References
4Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 16, 2003 |
| Grant date | Aug 3, 2004 |
| Priority date | — |
| Expiry date | Dec 2, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/14
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
An under bump metallurgy (UBM) structure is described. Two UBM mask processes are utilized. First, a top layer of copper (Cu) and/or a middle layer of nickel-vanadium (NiV) or chrome-copper (CrCu) is personalized by standard photoprocessing and etching steps utilizing a bump based size mask. This is followed by patterning an underlying seed layer with a second, larger mask, thereby preventing damage to the aluminum cap and seed layer undercut during the etching process.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.