Method for noise improvement in ellipsometers
US7342661B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 28, 2005 |
| Grant date | Mar 11, 2008 |
| Priority date | — |
| Expiry date | Nov 28, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/213
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A normalization procedure for an ellipsometric system having a rotating optical element such as a polarizer or compensator is disclosed. In operation, a first DC component is extracted from the measured output signals obtained during the first 180 degrees of rotation of the optical element and a second DC component is extracted from the output signals obtained during the second 180 degrees of rotation of the optical element. The first DC component is used to normalize the output signals obtained during the first 180 degrees of rotation of the optical element and the second DC component is used to normalize the output signals obtained during the second 180 degrees of rotation of the optical element.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.