Apparatus for measuring film thickness
US4606641A · kind A · utility
27Cited by
3References
4Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 30, 1984 |
| Grant date | Aug 19, 1986 |
| Priority date | — |
| Expiry date | Aug 30, 2004 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/0641
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An elliptically polarized monochromatic light is obtained from monochromatic light select unit and is reflected at an interface between an objective film and substrate. An extinction wavelength of the reflected light, when the amount thereof detected at photodetector becomes zero, is detected at control unit and the true thickness of the film is calculated from the detected extinction wavelength.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.