Surface profiling using a differential interferometer
US6580515B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 29, 2001 |
| Grant date | Jun 17, 2003 |
| Priority date | — |
| Expiry date | May 29, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/0675
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A differential interferometer is used to measure the step height between a reference region and at least one point in a measurement region using the relative phase difference as well as the measured reflectance from at least the point in the measurement region. The measured reflectance can be derived from the information provided by the differential interferometer. The measured reflectance from the reference region can also be used to provide a step height measured, where, e.g., the reference region has a changing thickness. Where the measurement region includes a composite material, e.g., copper and silicon dioxide, the step height between the reference region and the measurement region may be determined by including the area fraction or the height difference of the materials in the composite material in the final determination of the step height.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.