Slurry for multi-material chemical mechanical polishing
US6554878B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 14, 1999 |
| Grant date | Apr 29, 2003 |
| Priority date | — |
| Expiry date | Jun 14, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/3212
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
In a first aspect a slurry is provided for chemically mechanically polishing alumina and nickel iron to a common plane and in a second aspect a slurry is provided for additionally chemically mechanically polishing copper to a common plane. The slurry includes a first concentration of colloidal silica, a second concentration of potassium and/or sodium persulfate and a third concentration of ammonium persulfate. In the first aspect the first and second concentrations are tailored to chemically mechanically polish the alumina and the nickel iron at the same rate to a common plane and in the second aspect the slurry includes a third concentration of ammonium persulfate at a proper ratio to the potassium or sodium persulfate to chemically mechanically polish the copper at the same rate as the other materials to the same plane.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.