AVS 64th International Symposium & Exhibition
    Spectroscopic Ellipsometry Focus Topic Tuesday Sessions
       Session EL-TuP

Paper EL-TuP2
Comparing and Evaluating the Calculation Results of Measurement Uncertainty for Various Types of Rotating-element Spectroscopic Ellipsometers

Tuesday, October 31, 2017, 6:30 pm, Room Central Hall

Session: Spectroscopic Ellipsometry Poster Session
Presenter: YongJai Cho, Korea Research Institute of Standards and Science, Republic of Korea
Authors: Y.J. Cho, Korea Research Institute of Standards and Science, Republic of Korea
W. Chegal, Korea Research Institute of Standards and Science, Republic of Korea
H.M. Cho, Korea Research Institute of Standards and Science, Republic of Korea
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Various multi-channel rotating-element spectroscopic ellipsometers have excellent measurement abilities like real-time, high-precision, non-destructive, and contactless schemes, and as a result have been widely used in a semiconductor manufacturing process. With the development of semiconductor device process technologies, the thickness of the thin film used for these technologies is getting smaller and smaller and thus reaches a level of atomic layer and the shape of the nano pattern is changed from a two-dimensional structure into a three-dimensional structure and thus is becoming increasingly complicated. Therefore, for the rotating-element spectroscopic ellipsometers to be continuously used as a measurement tool for next-generation semiconductor industries, it is important to continuously enhance their measurement uncertainties. Recently, we developed the universal evaluations and expressions of measuring uncertainty for all types of rotating-element spectroscopic ellipsometers. We also introduced a general data-reduction process to represent the universal analytic functions of the combined standard uncertainties of the ellipsometric sample parameters. To solve the incompleteness of the analytic expressions, we formulated the estimated covariance for the Fourier coefficient means extracted from the radiant flux waveform using a new Fourier analysis. Our approach can be used for providing a method for calculating a theoretical model equation which may be applied to various kinds of multi-channel rotating-element spectroscopic ellipsometers and may determine a measurement confidence level thereof, that is, a theoretical equation on standard uncertainties of ellipsometric parameters determined on the basis of a series of observations for a sample. In this presentation, it will show that the calculation data of the combined standard uncertainty for the various types of the rotating-element spectroscopic ellipsometers are obtained using the universal expressions for the combined standard uncertainty. In particular, the calculation results for the dual-rotating-compensator spectroscopic ellipsometers will be compared and evaluated with the calculation results for the common single-rotating-element spectroscopic ellipsometers.