Differential evanescent light intensity imaging of nanothin films: simulation of the scattered field

Abstract

The evanescent optical field scattering simulation of a‐Se nanoparticles was obtained by the Maxwell equation solver FullWAVE and correlated to experimental a‐Se films nanoprofiles obtained by Differential Evanescent Light Intensity Imaging (DELI). The DELI method was used as an experimental imaging method of depth profiles for large areas, i.e., hundreds of mm2 of nanometer thick a‐Se layers. The comparison of light scattering simulation and thickness profiles obtained from the experiments corresponds to an optical scattering mechanism leading to evanescent light extraction by the a‐Se nanoparticles. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Height measurement of single nanoparticles based on evanescent field modulation

“…An evanescent wave, which is produced as light undergoes total reflection at a refractive index interface, is a vertically localised electromagnetic energy near the interface. The use of this form of illumination in microscopic observations is advantageous compared with far-field light in terms of the signal to noise (S/N) ratio, in near-interface measurements (Axelrod, 1989;Gankin et al, 2011;Kanda et al, 2007;Zettner, 2001). For example, in a study of CMP slurry dynamics, Idei et al (2011) used this technique to successfully measure phenomena related to the adhesion of SiO 2 particles to the wafer surface during the polishing process.…”