Sputter deposition and annealing of copper alloy metallization
US6037257A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 8, 1997 |
| Grant date | Mar 14, 2000 |
| Priority date | — |
| Expiry date | May 8, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/0002
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Copper and a small amount of an alloying metal such as magnesium or aluminum are cosputtered onto a substrate having oxide on at least a portion of its surface. Either the wafer is held at an elevated temperature during deposition or the sputtered film is annealed without the wafer being exposed to ambient. Due to the high temperature, the alloying metal diffuses to the surface. If a surface is exposed to a low partial pressure of oxygen or contacts silicon dioxide, the magnesium or aluminum forms a thin stable oxide. The alloying metal oxide encapsulates the copper layer to provide a barrier against copper migration, to form an adhesion layer over silicon dioxide, and to act as a seed layer for the later growth of copper, for example, by electroplating.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.