Method for endpoint detection for copper CMP
US6179691A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 6, 1999 |
| Grant date | Jan 30, 2001 |
| Priority date | — |
| Expiry date | Aug 6, 2019 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB24B57/02
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A copper isotope is added to the layer of copper that is deposited to form the metal interface. Radioactivity emitted by the copper layer is measured during copper polishing, endpoint of the copper CMP is reached when this radioactivity starts to rapidly decrease. Another approach is to measure the radioactivity of the copper slurry that is removed during copper polishing. Polishing end-point is reached when the copper slurry radioactivity starts to rapidly increase. Yet another approach is to add copper isotopes to the copper seed layer and measure the radioactivity emitted by the seed layer. Polishing end-point is reached when the radioactivity emitted by the seed layer starts to rapidly increase.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.