Via formation using oxide reduction of underlying copper
US6218303A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 11, 1998 |
| Grant date | Apr 17, 2001 |
| Priority date | — |
| Expiry date | Dec 11, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/76843
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Copper is the bulk interconnect metal in the manufacture of an integrated circuit in accordance with the damascene process. When copper is exposed through via apertures, carbon monoxide and hydrogen are used as reduction agents to convert black copper oxide to red copper oxide and the red copper oxide to copper. The integrated circuit is then transferred in a high vacuum to a sputter chamber so that re-oxidation does not occur before tantalum barrier metal can be deposited. As a result, a good tantalum-copper electrical contact can be made without risking embedding copper in oxide sidewalls (whence it could migrate to active circuit regions and impair device reliability).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.