Method of using additives with silica-based slurries to enhance selectivity in metal CMP
US5614444A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jun 6, 1995 |
| Grant date | Mar 25, 1997 |
| Priority date | — |
| Expiry date | Jun 6, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/3213
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method of using additives with silica-based slurries to enhance metal selectivity in polishing metallic materials utilizing a chemical-mechanical polishing (CMP) process. Additives are used with silica-based slurries to passivate a dielectric surface, such as a silicon dioxide (SiO.sub.2) surface, of a semiconductor wafer so that dielectric removal rate is reduced when CMP is applied. The additive is comprised of at least a polar component and an apolar component. The additive interacts with the surface silanol group of the SiO.sub.2 surface to inhibit particles of the silica-based slurry from interacting with hydroxyl molecules of the surface silanol group. By applying a surface passivation layer on the SiO.sub.2 surface, erosion of the SiO.sub.2 surface is reduced. However, the metallic surface is not influenced significantly by the additive, so that the selectivity of metal removal over oxide removal is enhanced.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.