A 2-dimensional thickness measurement ellipsometer based on the liquid crystal variable retarder

Fangfang Meng, Xuejian Wu, Yan Li

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

A 2-dimensional thickness measurement ellipsometer based on the liquid crystal variable retarder (LCVR) is proposed and setup in order to provide precise, real-time measurement in a manufacturing environment. Images are collected sequentially by CCD camera with respect to pre-determined polarization state of incident light derived by the LCVR attached with compensator. A phase-shifting algorithm and a Fourier series approach algorithm are used to obtain full-field distributions of the ellipsometric parameters, and then a polarization model (ambient-film-substract) is used to calculate the thickness of a thin film in two dimensions precisely and quickly. Theoretically, the speed and precision of this method benefit from applying voltage on the LCVR to produce polarization modulation that is able to avoid mechanical vibrations that could affect the accuracy of the measurements. The experimental results verify the ability and performance of the 2-dimensional thickness measurement ellipsometer.

Original languageEnglish (US)
Title of host publicationOptical Metrology and Inspection for Industrial Applications III
EditorsSen Han, Toru Yoshizawa, Song Zhang
PublisherSPIE
ISBN (Electronic)9781628413496
DOIs
StatePublished - 2014
Externally publishedYes
EventOptical Metrology and Inspection for Industrial Applications III - Beijing, China
Duration: Oct 9 2014Oct 11 2014

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
Volume9276
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X

Conference

ConferenceOptical Metrology and Inspection for Industrial Applications III
Country/TerritoryChina
CityBeijing
Period10/9/1410/11/14

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

Keywords

  • Ellipsometry
  • Liquid crystal variable retarder
  • Thickness measurement

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