Reduce or eliminate IMC cracking in post wire bonded dies by doping aluminum used in bond pads during Cu/Low-k BEOL processing
US7205673B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 18, 2005 |
| Grant date | Apr 17, 2007 |
| Priority date | — |
| Expiry date | Nov 18, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/351
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A bond pad structure which includes an aluminum bond pad which include one or more dopants that effectively control the growth of IMC to a nominal level in spite of high tensile stresses in the wafer. For example, aluminum can be doped with 1–2 atomic % of Mg. Alternatively, Pd or Si can be used, or elements like Cu or Si can be used as the dopant in order to reduce the overall tensile stresses in the wafer. This can control the abnormal growth of IMC, thus arresting the IMC crack formation. A combination of dopants can be used to both control the tensile stresses and also slightly alter the gold-Aluminum interface thus enabling a uniform and thin IMC formation. This tends to reduce or eliminate any voiding or cracking which would otherwise occur at the wire bond transfer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.