Cobalt silicidation using tungsten nitride capping layer
US6083817A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 2, 1999 |
| Grant date | Jul 4, 2000 |
| Priority date | — |
| Expiry date | Jun 2, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/902
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A substantially inert capping layer of tungsten nitride is deposited on cobalt layers prior to silicidation, thereby avoiding any substantial interaction with cobalt. The tungsten nitride capping layer also functions as a diffusion barrier preventing oxygen from reaching the silicidation area. The resulting cobalt silicides layer exhibit lower resistivity than those formed employing a titanium capping layer. Embodiments include rapid thermal annealing to initially form a layer of cobalt monosilicide consuming a portion of the cobalt layer, removing the tungsten nitride and unreacted cobalt layer, and rapid thermal annealing again to convert the cobalt monosilicide layer to a low resistivity layer of cobalt disilicide.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.