Method to prevent leaving residual metal in CMP process of metal interconnect
US6599173B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 30, 2000 |
| Grant date | Jul 29, 2003 |
| Priority date | — |
| Expiry date | Sep 8, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P80/30
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A CMP slurry for and method of polishing a semiconductor wafer during formation of metal interconnects are disclosed. The present invention utilizes a first slurry comprising a first oxidizer, preferably ferric nitrate, to remove the excess metal of the metal interconnect but which leaves the metal residues on the surface of the wafer. A second slurry comprising another oxidizer, preferably potassium iodate solution, having a greater affinity to both the metal residue and the liner material than the underlying dielectric is used to remove the metal residue and liner material with significantly reduced scratching of the underlying dielectric. The more robust metal interconnects formed utilizing the present invention is effective in lowering the overall resistance of a wafer, reducing the number of shorts, and provides greater protection of the underlying dielectric. Overpolishing of the wafer and its associated problems are avoided.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.