Apparatus for measuring the depth of fine engraved patterns
US4615620A · kind A · utility
38Cited by
2References
13Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 24, 1984 |
| Grant date | Oct 7, 1986 |
| Priority date | — |
| Expiry date | Dec 24, 2004 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/22
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An apparatus for measuring in a non-contact manner the depth of pits and grooves formed by etching in periodic patterns on the surface of a substrate. The measurement is based on the detection of the intensity of a diffraction ray excluding that of the 0th order through the irradiation of a light beam with variable wave length to the sample. Whereas, the conventional measuring system is sensitive to a diffraction ray of the 0th order, i.e., the major component of the reflected light, that hampers the detection of a higher order diffraction ray carrying information of the depth.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.