Apparatus for measuring the thickness of a thin film with angle detection means
US4893024A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 25, 1988 |
| Grant date | Jan 9, 1990 |
| Priority date | — |
| Expiry date | May 25, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/0675
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An apparatus for measuring the thickness of a thin film utilizing an interferometric method includes a light source for generating a monochromatic light beam, a scanner for scanning the light beam on a thin film in such a manner that an incident angle thereto is continuously varied from .alpha. to (-.alpha.), a first detector for detecting the incident angle of the light beam and a second detector for detecting an interference pattern caused by light beams reflected from the top and bottom surfaces of the thin film. The thickness of the thin film is obtained in accordance with a geometrical optical relationship defined between adjacent fringes contained in the detected interference pattern.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.