Spectroscopy: Ellipsometry (multiple wavelengths)

Benefit description

We have a variable angle spectroscopic ellipsometer (J.A. Woollam Co.) and modeling software (WVase 32). It allows to optically characterize massive or thin film materials. In particular, it allows obtaining the refractive index (n and k), the thickness of the thin films, the surface and interfacial roughness in the case of multilayers, the optical anisotropy or the degree of oxidation, density and composition of the layer, both in alloys and in phase-separated and nanostructured composites. Finally, in doped materials, it is possible to determine the concentration of the dopant. It is also possible to correlate these properties with the structure of the materials if the appropriate know-how is available. The operating range is 270-1700 nm, using a Xe source and two specific fibers for UV/VIS and VIS/NIR. The system has an automatic retarder for measuring delta values between 0 and 360º and finally, it has a reduction device that allows the analysis of areas as small as 200 x 200 um^2. In addition, a sample holder has been implemented last year that allows samples to be heated up to temperatures of 500ºC.