Multi-detector ellipsometer and process of multi-detector ellipsometric measurement

摘要

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./!