Method and apparatus for measuring a change in the thickness of polishing pads used in chemical-mechanical planarization of semiconductor wafers
US5801066A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 6, 1997 |
| Grant date | Sep 1, 1998 |
| Priority date | — |
| Expiry date | Mar 6, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/0683
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
The inventive apparatus is a wafer planarizer that has a movable platen, a polishing pad positioned on the platen, a wafer carrier positioned opposite the polishing pad, and a measuring device that is engagable with the polishing pad. The polishing pad decreases as the wafer is conditioned in a straight line correlation with the resulting polishing rate of a wafer. The wafer is attachable to the wafer carrier, and it may be moved with the carrier to be selectively engaged with the polishing pad to planarize the wafer at a wafer polishing rate under a set of wafer polishing operating parameters. After the wafer is planarized, the pad is conditioned by removing a layer of material from the planarizing surface of the pad under a set of conditioning parameters. The measuring device measures the decrease in the thickness of the polishing pad after the pad is conditioned, and it correlates the actual decrease in pad thickness with an expected change in pad thickness. When the same pad conditioning parameters are used from one pad conditioning cycle to the next, a difference between the actual decrease in pad thickness and the expected change in pad thickness indicates a change in operati…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.