M. Janosov and P. Petrik
Hungarian Academy of Sciences
Research Centre for Natural Sciences
Institute for Technical Physics and Materials Science
(MTA TTK MFA)
Spectroscopic Ellipsometry (SE) is a highly sensitive, nondestructive, label-free optical measuring technique. With SE it is possible to determine many optical properties of thin films (e.g. the thickness on the subnanometer scale). SE utilizes the polarization state’s change of the reflected light from the sample’s surface. In most cases, SE is used on opaque (mainly semiconductor) substrates. In these cases it is a valid approximation that the sample substrate is semi-infinite, since only the evanescent field penetrates into the very top part of the sample. This is much different when measuring transparent (glass, quartz, etc.) samples because of the so called background reflection effect, which must be eliminated for an accurate measurement.
SE can be used as a reference method for different biochemical sensing techniques (SPR, OWLS, etc). These methods typically work with transparent substrates though. That is the reason why it is important to measure on transparent substrates as successfully as possible. In this presentation an overview of our recent results is given.