Measuring method for ellipsometric parameter and ellipsometer
US5335066A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 7, 1993 |
| Grant date | Aug 2, 1994 |
| Priority date | — |
| Expiry date | Oct 7, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/211
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Movable optical parts included in an ellipsometer are omitted to increase the measurement speed and maintain constant, high measurement precision in film thickness measurement processing. A beam is radiated from a light source section onto a measurement target. A reflected beam having an elliptically polarized beam reflected by the measurement target is divided into four light components polarized in different directions. The optical intensities of the respective polarized light components are detected. Of the four detected optical intensities, one having the minimum value is omitted, and ellipsometric parameters .psi. and .DELTA. are calculated by using the remaining three optical intensities having the largest values. The ellipsometer comprises only stationary optical parts without using any movable optical parts. The polarization directions of the respective polarized light components, from which four optical intensities are obtained, are set at angles of 90.degree., 0.degree., +45.degree., and -45.degree. with respect to a reference direction. A composite beam splitter is used to extract the four polarized light components.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.