Optical measurement system using polarized light
US6134011A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 15, 1998 |
| Grant date | Oct 17, 2000 |
| Priority date | — |
| Expiry date | Sep 15, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/211
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An optical measurement system for evaluating the surface of a substrate or the thickness and optical characteristics of a thin film layer overlying the substrate includes an intensity stabilized light source configured to generate a stabilized light beam, a polarizing element for polarizing the light beam emanating from the light source, and a detection system for measuring the light reflected from the substrate The measurement system includes a polarizing beam-splitter for splitting the light reflected from the substrate into s-polarized light and p-polarized light. The measurement system further includes two optical sensors for separately measuring the amplitude of the s-polarized light and the intensity of the p-polarized light and a third detector for measuring either the phase difference between the s-polarized light and the p-polarized light or the reflection angle of the light reflected from the substrate. A control system analyzes the measured amplitude of the s-polarized light and the p-polarized and either the phase-difference or the reflection angle to determine changes in the topography of substrate or changes in the thickness or optical characteristics of the thin film…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.