Full Content is available to subscribers

Subscribe/Learn More  >
Proceedings Article

Koehler illumination in high-resolution optical metrology

[+] Author Affiliations
Yeung Joon Sohn, Brian M. Barnes, Lowell Howard, Richard M. Silver, Ravikiran Attota, Michael T. Stocker

National Institute of Standards and Technology

Proc. SPIE 6152, Metrology, Inspection, and Process Control for Microlithography XX, 61523S (March 24, 2006); doi:10.1117/12.655126
Text Size: A A A
From Conference Volume 6152

  • Metrology, Inspection, and Process Control for Microlithography XX
  • Chas N. Archie
  • San Jose, CA | February 19, 2006

abstract

Accurate preparation of illumination is critical for high-resolution optical metrology applications such as linewidth and overlay measurements. To improve the detailed evaluation and alignment of the illumination optics, we have separated Koehler illumination into three components. The three Koehler illumination components are defined as full field spatial intensity variation (Koehler factor 1), angular intensity homogeneity (Koehler factor 2), and wavefront phase/intensity homogeneity (Koehler factor 3). We have also proposed a field aperture pattern transfer method to analyze the illumination properties with respect to systematic variations, such as the shape of the source, the intensity distribution at the back focal plane, and the displacements of elements along and off the optical axis. These factors were investigated in both ideal and practical illumination systems. In particular, any angular asymmetry in the illumination proves to have a detrimental effect upon the distribution of light that illuminates the target. Wavefront asymmetry is also studied in the context of an optical system with a coherent or partially coherent light source.

© (2006) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Citation

Yeung Joon Sohn ; Brian M. Barnes ; Lowell Howard ; Richard M. Silver ; Ravikiran Attota, et al.
"Koehler illumination in high-resolution optical metrology", Proc. SPIE 6152, Metrology, Inspection, and Process Control for Microlithography XX, 61523S (March 24, 2006); doi:10.1117/12.655126; http://dx.doi.org/10.1117/12.655126


Access This Proceeding
Sign in or Create a personal account to Buy this proceeding ($15 for members, $18 for non-members).

Figures

Tables

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging & repositioning the boxes below.

Related Book Chapters

Topic Collections

Advertisement
  • Don't have an account?
  • Subscribe to the SPIE Digital Library
  • Create a FREE account to sign up for Digital Library content alerts and gain access to institutional subscriptions remotely.
Access This Proceeding
Sign in or Create a personal account to Buy this proceeding ($15 for members, $18 for non-members).
Access This Proceeding
Sign in or Create a personal account to Buy this article ($15 for members, $18 for non-members).
Access This Chapter

Access to SPIE eBooks is limited to subscribing institutions and is not available as part of a personal subscription. Print or electronic versions of individual SPIE books may be purchased via SPIE.org.