Another seminar is coming "Spectroscopic ellipsometry for thin films characterization in UV-VIS-NIR and mid-infrared spectral region"

We don't slow down with online seminars and we stay within the topic of Material Engineering. 

Details about the next seminar:

• Topic: "Spectroscopic ellipsometry for thin films characterization in UV-VIS-NIR and mid-infrared spectral region"
• Led by: prof. Janusz Jaglarz
• Date: 14.05.2024
• Time: 15:00
• Location: MS Teams - link to the meeting (no prior registration is need)
• Language: English

Abstract:

"In modern thin-film technologies, optical methods are used to measure the thickness, porosity and roughness of layers, such as transmission and reflection spectrophotometry and spectroscopic ellipsometry, which use the spectral range of UV-VIS-NIR (190-2500 nm) and IR (2.5 up to 25 mm).

Ellipsometry is an optical method for examining surfaces and thin layers that uses the phenomenon of changing the polarization state as a result of reflection from the examined body surface. The reflected beam is generally elliptically polarized. If the reflection occurs from a flat boundary separating two infinite media, the change in the polarization state depends only on the optical properties (dielectric constants) of these media and the angle of incidence and wavelength of the light. If on a flat boundary separating two infinite media there is a thin layer with optical properties different from the optical properties of these two media, then the change in the polarization state also depends on the optical properties and thickness of this layer. Therefore, determining the parameters defining the state of elliptical polarization of the reflected light beam provides us with information about the "state of the surface" on which the reflection takes place.

In my speech, I will present the possibilities of using ellipsometry for testing material surfaces and thin layers. The results of ellipsometric measurements carried out in a wide spectral range from ultraviolet to mid-infrared will be presented. These measurements made it possible to determine the optical constants of material layers and substrates, and by determining the absorption coefficient, also the dispersion of absorption coefficients, thus enabling the description of electronic transitions in the UV-VIS areas, and in the IR area also vibrational transitions."