Thin film layers control is extremely important to many technology-based industries. We will look by means of industry examples at two principal optical measurement types; spectral reflectometry and optical profilometry. The aim is to provide you with clarity into the physical working principles, when to use these techniques, and how to apply them to a variety of samples.

Thin-film interference lies at the core of optical analysis, which allows for high throughput and non-destructive measurements with no sample preparation. Filmetric’s film thickness measurement tools are based upon spectral reflectance where light is reflected off the sample and then analyzed over a broad range of wavelengths. This optical method allows to obtain fast and accurate information on the film thickness, uniformity and optical properties without touching nor damaging the surface. White light interferometry (WLI) is a complementary technique used to measure the 3D topography surfaces with very high precision. With this technology, it is possible to measure surface features like step heights and roughness with sub-nanometer resolution.