Method for measuring surface profile, and apparatus using the same
US7852489B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Jan 26, 2007 |
| Grant date | Dec 14, 2010 |
| Priority date | — |
| Expiry date | Nov 5, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/2441
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A reference plane is arranged in a posture obliquely tilted at an optional angle relative to a traveling direction of a light-beam, so that an interference fringe is generated from the reflected light-beams which are reflected from a target plane and the reference plane and, then, return on a single optical path. An image of the interference fringe is taken by a CCD camera to acquire intensity value data of each pixel. A phase of an interference fringe waveform is obtained for each pixel by a CPU by fitting the intensity value data to a model equation expressing the interference fringe waveform, where the intensity value data contain that of each pixel and those of the pixels in the vicinity of the relevant pixel, on assumption that DC components, AC amplitudes and phases of the interference fringe waveforms are respectively constant in the vicinity of the relevant pixel. The obtained phase is converted into a height to measure a surface profile.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.