Eddy current sensor and polishing method
US9632061B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 28, 2013 |
| Grant date | Apr 25, 2017 |
| Priority date | — |
| Expiry date | Jan 10, 2035 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/0002
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An eddy current sensor is used for detecting a metal film (or conductive film) formed on a surface of a substrate such as a semiconductor wafer. The eddy current sensor is disposed near the metal film or the conductive film formed on the substrate to detect an eddy current generated in the metal film or the conductive film. The eddy current sensor includes a plurality of coils having different sizes formed by winding a wire or a conductive material. The plurality of coils includes an inner coil and an outer coil spaced from each other, and the outer coil is configured to surround the inner coil. The plurality of coils are configured to detect respective eddy currents generated in the metal film or the conductive film.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.