Reflectance spectroscopic apparatus with toroidal mirrors
US6128085A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 19, 1999 |
| Grant date | Oct 3, 2000 |
| Priority date | — |
| Expiry date | Oct 19, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J4/00
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An apparatus uses reflectance spectrophotometry to characterize a sample having any number of thin films. The apparatus uses two toroidal mirrors in an optical relay to direct light reflected by the sample to a spectroscopic device. A computer then analyzes the reflected spectrum to characterize the optical properties of the sample. The optical relay allows a range of angles of reflection from the sample, and has no chromatic aberration. The optical relay is also arranged so that the non-chromatic aberration is minimized. For polarization-based measurements polarizing elements can be used in the apparatus and the spectroscopic device can be a spectroscopic ellipsometer. The sample is mounted on a movable stage so that different areas of the sample may be characterized. Furthermore, a deflector and a viewer are used to allow the operator of the apparatus to view the region of the sample under study.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.