Ellipsometry and IR Spectrophotometry

Scientist in charge

Dr. Carlos Pecharromán García (Senior Researcher)

Technician

Pedro Rodríguez-Pascual García (Research Assistant)

Contact 

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Location

Lab 129 (first floor)
ICMM-CSIC, C/Sor Juana Inés de la Cruz 3, 28049 Madrid, España

Measurements and Equipment

Bruker Vertex 70V Spectrophotometer with microscope Hyperion 2000: The experimental setup allows to perform spectral analysis on solid samples (both in bulk, film and powder form) in a spectral range from 50 to 18000 cm-1 ( 200 to 0.55 um). Typically the analyses are performed in transmission (KBr, polyethylene or CSI). In addition, adjustable cells are available for diffuse reflection (rough surfaces), specular reflection (smooth surfaces) at normal and grazing incidence (with polarized light), internal reflection spectroscopy (attenuated total reflection, ATR). Small area mapping measurements can also be performed with the Hyperion microscope in both transmission and reflection (ATR, specular with Cassegrain objective and grazing angle).

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Ellipsometer GES 5E from SOPRA, provided with a Xe-lamp and a goniometer, which allows to adjust the angle of incidence on the sample, covering a spectral range from 190 nm to 2000 nm. This Ellipsometer is able to determine the change of the state of polarization of a beam of polarized light produced by the reflection on a polished surface. This technique is especially recommended to determine the thickness and refractive index of thin films (1 nm to 1 micron). It is required a perfectly polished sample with a flat surface.  In addition to ellipsometry, it can make photometric measurements at a fixed polarization state (reflectance and transmittance) under variable angle. For this technique, samples must be very smooth.

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Allowed samples

IR and visible samples can be measured in powdered or solid state. Different analytical techniques are chosen depending on the optical nature of the samples as well as the state. Most of the measurements are non-destructive.
For ellipsometry and reflectometry, samples must be flat and smooth.

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