Self-calibrating beam profile ellipsometer
US7054006B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 19, 2004 |
| Grant date | May 30, 2006 |
| Priority date | — |
| Expiry date | May 8, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J4/00
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A real-time calibration method for beam profile ellipsometry systems includes projecting an electromagnetic probe beam having a known polarization state though an objective lens onto the surface of a subject and collecting the reflected probe beam using the same objective. The reflected probe beam is then passed through a rotating compensator and analyzer before being received by a detector. A processor performs a harmonic analysis on the detector output to determine normalized Fourier coefficients. The processor uses Fourier coefficients to measure the retardation δB and the azimuth angle QB of the objective lens; and uses the retardation δB and the azimuth angle QB to identify the ellipsometric effects of the objective lens.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.