Measurement of thin films by polarized light
US3985447A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 29, 1975 |
| Grant date | Oct 12, 1976 |
| Priority date | — |
| Expiry date | Aug 29, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/211
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In order to measure the thickness and refractive index of a thin film on a substrate, such as a film of silicon dioxide on a substrate of silicon, a beam of substantially monochromatic polarized light is directed on the film. The reflected light is transmitted through an optical compensator and an optical analyzer both of which are rotating at different angular speeds, .omega..sub.A and .omega..sub.C, respectively; and the transmitted optical intensity is measured as a function of time. A Fourier analysis, for example, of the profile of this optical intensity vs. time can then be used for determining the Stokes parameters of the light reflected by the thin film and thereby also the thickness and refractive index of the film.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.