Share Email Print

Proceedings Paper

White-light interferometry with reference signal
Author(s): Joanna Schmit; Artur G. Olszak; Shawn D. McDermed
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

White light interferometer (WLI) has become a common tool for measuring surfaces with large height range and/or roughness. Typically, the object is scanned through focus, thus varying the optical path difference (OPD) between the object and reference beams. The rate of the OPD change affects the quality and accuracy of the surface measurement. For high quality measurements a scanning device is often enhanced by a closed loop feedback while the scanning speed is assumed to be known and constant. In this paper we describe a white light interferometer that yields excellent results without requiring a high-end scanner. These results are achieved by embedding an additional interferometer with a long coherence length source that provides an interferometric reference signal that is used to monitor the motion of the scanner during each measurement in real time. The information about the scanner motion is then used in a WLI algorithm. This yields significant improvements in both the accuracy and repeatability of topography measurements.

Paper Details

Date Published: 20 June 2002
PDF: 8 pages
Proc. SPIE 4777, Interferometry XI: Techniques and Analysis, (20 June 2002); doi: 10.1117/12.472209
Show Author Affiliations
Joanna Schmit, Veeco Metrology (United States)
Artur G. Olszak, Veeco Metrology (United States)
Shawn D. McDermed, Veeco Metrology (United States)

Published in SPIE Proceedings Vol. 4777:
Interferometry XI: Techniques and Analysis
Katherine Creath; Joanna Schmit, Editor(s)

© SPIE. Terms of Use
Back to Top