Magnetron sputtered metallization of a nickel silicon alloy, especially useful as solder bump barrier
US7321140B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 11, 2005 |
| Grant date | Jan 22, 2008 |
| Priority date | — |
| Expiry date | Feb 24, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/3025
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A nickel silicon alloy barrier layer formed between a metal bonding pad on an integrated circuit and a tin-based solder ball, for example, a lead-free solder. The nickel silicon alloy contains at least 2 wt % silicon and preferably less than 20 wt %. An adhesion layer may be formed between the barrier layer and the bonding pad. For copper metallization, the adhesion layer may contain titanium or tantalum; for aluminum metallization, it may be aluminum. The nickel silicon alloy may be deposited by magnetron sputtering. Commercially available NiSi4.5% sputter targets have provided a superior under-bump metallization (UBM) with lead-free tin solder bumps. Dopants other than silicon/may be used to reduce the magnetic permeability and provide other advantages of the invention.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.