Method and apparatus for simultaneously improving the electromigration reliability and resistance of damascene vias using a controlled diffusivity barrier
US6306732A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 9, 1998 |
| Grant date | Oct 23, 2001 |
| Priority date | — |
| Expiry date | Oct 9, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/927
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
An apparatus for improving electromigration reliability and resistance of a single- or dual-damascene via includes an imperfect barrier formed at the bottom of the via, and a stronger barrier formed at all other portions of the via. The imperfect barrier allows for metal atoms, such as copper atoms, to flow therethrough when the electromigration force pushes the metal atoms against the barrier. That way, the metal atoms that are pushed away from the downstream side of the barrier are replaced by metal atoms that flow through the barrier from the upstream side of the barrier. The imperfect barrier may be formed by biasing a wafer, and having the atoms resputter from the bottom of the via and adhere to the sidewalls of the via. The imperfect barrier may also be formed by a two-layered barrier, where a first layer corresponds to a good step coverage, poor barrier, and where the second barrier corresponds to a poor step coverage, good barrier. The imperfect barrier may also be formed by depositing the barrier conformally, and providing a directional etch to the portions of the barrier that are deposited to the bottom of the via.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.