Method of detecting characteristics of films using eddy current
US7714572B2 · kind B2 · utility
8Cited by
21References
19Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 30, 2006 |
| Grant date | May 11, 2010 |
| Priority date | — |
| Expiry date | May 30, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R23/10
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A method of detecting a characteristic (such as thickness) of first and second films formed on a substrate includes supplying a sensor coil with a first alternating current having a first frequency when detecting the first film, and a second alternating current having a second frequency when detecting the second film. An eddy current is thereby generated in the first film or the second film. An impedance across the sensor coil is measured, and the characteristic of any one of the first film and the second film is detected based on the impedance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.