Details

Autor(en) / Beteiligte

• Kovalev, V. I.
• Rukovishnikov, A. I.
• Kovalev, S. V.
• Kovalev, V. V.
• Rossukanyi, N. M.

Titel

An achromatic four-mirror compensator for spectral ellipsometers

Ist Teil von

• Optics and spectroscopy, 2017-07, Vol.123 (1), p.168-171

Ort / Verlag

Moscow: Pleiades Publishing

Erscheinungsjahr

2017

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Measurement and calculation results are presented that confirm that design four-mirror compensators can be designed for the spectral range of 200–2000 nm that is widely used in modern spectral ellipsometers. Measurements and calculations according to standard ellipsometric programs have been carried out on a broadband LED spectral ellipsometer with switching of orthogonal polarization states. Mirrors with the structure of glass substrate/Al 2 O 3 layer (20–30 nm thick)/Al layer (150 nm thick)/upper Al 2 O 3 layer (with specified thickness d ) have been prepared by vacuum-evaporation method. It is shown that the phase-shift spectra of a four-mirror compensator, two mirrors of which have a native oxide 5.5 nm thick and the two others of which have an oxide layer 36 nm thick, measured on the ellipsometer, are flattened in comparison with similar spectra of a compensator, all four mirrors of which have a native oxide, especially in the short-wavelength spectral region. The results of calculating the phase-shift spectra of the four-mirror compensator with six variable parameters (angles of incidence of radiation on the mirrors and thicknesses of oxide layers on four mirrors) are presented. High-quality achromatization in a wide spectral range can be achieved for certain sets of parameters.