Applications of ellipsometry in nanoscale science: Needs, status, achievements and future challenges

This paper provides an overview of the relationship between optical ellipsometric measurements and nanoscale science. This relationship is discussed by analyzing published papers, patents and nanomaterials investigated in laboratories and constituting commercial products. Specific challenges and needs for advancing ellipsometry exploitation in nanotechnology are also discussed in the frame of nanometrology standardization. The ellipsometric characterization of plasmonic gold nanoparticles supported on a silicon substrate is used as an example to discuss various issues related to the optical characterization of nanomaterials, i.e., the detection of buried interfaces, size effects on the dielectric function and the monitoring in real time of nanoparticles growth.