title: High-resolution imaging ellipsometer.
abstract: We report on a novel imaging ellipsometer using a high-numerical-aperture (NA) objective lens capable of measuring a two-dimensional ellipsometric signal with high resolution. Two-dimensional ellipsometric imaging is made possible by spatial filtering at the pupil plane of the objective. A Richards-Wolf vectorial diffraction model and geometrical optics model are developed to simulate the system. The thickness profile of patterned polymethyl methacrylate is measured for calibration purposes. Our instrument has a sensitivity of 5 A and provides spatial resolution of approximately 0.5 microm with 632.8-nm illumination. Its capability of measuring refractive-index variations with high spatial resolution is also demonstrated.
authors.affiliation: Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis 55455, USA. qzhan@ece.umn.edu
authors.forename: Qiwen
authors.initials: Q
authors.lastname: Zhan
authors.forename: James R
authors.initials: JR
authors.lastname: Leger