Apparatus and method for measuring the depth of fine engraved patterns
USRE33424E · kind E · reissue
6Cited by
2References
26Claims
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Key dates
| Filing date | Oct 7, 1988 |
| Grant date | Nov 6, 1990 |
| Priority date | — |
| Expiry date | Oct 7, 2008 |
Classification
- Technology area (CPC —)General
Abstract
An apparatus .Iadd.and method .Iaddend.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.
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