Copper target for sputter deposition
US6139701A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 18, 1999 |
| Grant date | Oct 31, 2000 |
| Priority date | — |
| Expiry date | Mar 18, 2019 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23C14/3414
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A copper sputtering target is provided for producing copper films having reduced in-film defect densities. In addition to reducing dielectric inclusion content of the copper target material, the hardness of the copper target is maintained within a range greater than 45 Rockwell. Within this range defect generation from arc-induced mechanical failure is reduced. Preferably hardness is achieved by limiting grain size to less than 50 microns, and most preferably to less than 25 microns. The surface roughness preferably is limited to less than 20 micro inches, or more preferably, less than 5 micro inches to reduce defect generation from field-enhanced emission. This grain size range preferably is achieved by limiting the purity level of the copper target material to a level less than 99.9999%, preferably within a range between 99.995% to 99.9999%, while reducing particular impurity levels.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.