Title: Spectroscopic Ellipsometry and its Recent Applications
Speaker: Dr. Nina Hong (J.A. Woollam Co.)
Date: Friday, November 16, 2018
Time: 10:00 am – 11:00 am
Location: IESB (Bldg. 2102), Rm. 201
Abstract: Spectroscopic ellipsometry (SE) is a proven optical measurement technique for thin film characterization. Ellipsometry measures the polarization state change upon sample reflection or transmission. It is primarily used to determine film thickness and material optical properties such as refractive index and extinction coefficient. However, it is also applied to characterize surface roughness, index grading, compound composition, multi-layer stacks, doping concentration, anisotropy, metamaterials, and other properties associated with optical response. Commercially available wavelength range is very wide from vacuum ultra-violet (140nm) to terahertz (~3mm), which enables us to obtain the material properties in the desired wavelength range. Lately, orientation dependent optical properties caused by sample birefringence and dichroic are of great interest. The generalized or Mueller Matrix ellipsometry is able to measure the cross polarization caused by the anisotropic samples. Thus, interesting optical activities such as retardance, diattenuation, and chirality can be determined by ellipsometry. This talk will review the basic principles of SE and introduce various recent applications.
Bio: Nina Hong received her Bachelor and Master degrees in physics from the Hanyang University-Seoul, Korea and her PhD in physics from the University of Lincoln, NE. She joined the J.A. Woollam Company in 2012 as an applications physicist. Her research at the J.A. Woollam Company has focused on new applications of spectroscopic ellipsometry. Her recent publications are on Mueller Matrix characterization of birefringent flexible substrates, ellipsometry and porosimetry modeling on nanoporous surfaces, and total internal reflection SE for hyperbolic metamaterials.
POC: Hyun Jung Kim (hyunjung.kim@nasa.gov, 42588) coordinating with AMDSB (Advanced Measurements and Data Systems Branch)