For the characterization of transparent and semi-transparent thin or thick films in terms of film thickness and optical properties, optical methodologies are the most popular ones, offering fast, non destructive and highly accurate measurements. The mostly used ones are

• Single Wavelength Interferometry (SWI),

• Single Wavelength Ellipsometry (SWE),

• White Light Reflectance Spectroscopy (WLRS) and

• Spectrometric Ellipsometry (SE).

The Film Characterization tools designed and developed by Thetametrisis are based on White Light Reflectance Spectroscopy (WLRS). WLRS analyses the reflected interference spectrum from a sample, and offers real time measurements of film thickness, refractive index and absorption coefficients of thin and thick transparent or semitransparent films and stack of films at very low cost compared to Ellipsometric techniques without compromise in accuracy and application range. The particular design of Thetametrisis tools, offer amongst others very high level of integration of the measurement set-up, high flexibility, state of the art software. Furthermore it is possible to extend their use in various applications such as in liquids and in controlled (e.g. temperature and/or gas ambient) environments.

The algorithms implemented in FR-Monitor, the software supplied with every FR-tool, support not only single film measurements over a reflective substrate, but also multilayer stacks over a reflective substrate or even suspended single or multilayer films stacks. Furthermore, depending on the FR-tool configuration, typical absorbance/transmittance fluorescence and reflectance measurements are supported.

A detail presentation of the principle of operation and the experimental set-up of Absorbance/Transmittance, Fluorescence, Irradiation, and Reflectance measurements, along with Single Wavelength Interferometry and White Light Reflectance Spectroscopy methodologies are presented in detail in: