Multi-detector ellipsometer and process of multi-detector ellipsometric measurement
US5757671A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 5, 1996 |
| Grant date | May 26, 1998 |
| Priority date | — |
| Expiry date | Aug 5, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/211
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An ellipsometer comprising several photodetectors and an electronic processing unit (4) produces a beam of light modulated at a modulation frequency (Fm) which is reflected by a sample. The photodetectors measure fluxes from parts of the reflected luminous beam, producing measured analog signals in input channels (6), and the electronic processing unit (4) calculates physical parameters of the sample. This electronic processing unit (4) comprises a multiplexing and digitizing unit (7) successively switching to the input channels (6) at a switching frequency (Fe) and a sequencer (19). The sequencer (19) comprises means (24, 35) to allow setting the switching frequency (Fe) as a multiple of the modulation frequency (Fm). The ellipsometer takes optical measurements in real time, in particular for depositing films on substrates.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.