Articles

Sensitivity of scanning electron microscope width measurements to model assumptions

[+] Author Affiliations
John S. Villarrubia

National Institute of Standards and Technology, 100 Bureau Drive, Stop 8212, Gaithersburg, Maryland 20899

Zejun J. Ding

University of Science and Technology of China, Hefei National Laboratory for Physical Science at Microscale and Department of Physics, Hefei 230026, Anhui, China

J. Micro/Nanolith. MEMS MOEMS. 8(3), 033003 (August 17, 2009). doi:10.1117/1.3190168
History: Received April 20, 2009; Accepted June 02, 2009; Published August 17, 2009
Text Size: A A A

The most accurate width measurements in a scanning electron microscope (SEM) require raw images to be corrected for instrumental artifacts. Corrections are based on a physical model that describes the sample-instrument interaction. Models differ in their approaches or approximations in the treatment of scattering cross sections, secondary electron generation, material properties, scattering at the surface potential barrier, etc. Corrections that use different models produce different width estimates. We have implemented eight models in the Java Monte Carlo simulator for secondary electrons (JMONSEL) SEM simulator. Two are phenomenological models based on fitting measured yield versus energy curves. Two are based on a binary scattering model. Four are variants of a dielectric function approach. These models are compared to each other in pairwise simulations in which the output of one model is fit to the other by using adjustable parameters similar to those used to fit measured data. The differences in their edge position parameters is then a measure of how much these models differ with respect to a width measurement. With electron landing energy, beam width, and other parameters typical of those used in industrial critical dimension measurements, the models agreed to within ±2.0nm on silicon and ±2.6nm on copper in 95% of comparisons.

Figures in this Article
© 2009 Society of Photo-Optical Instrumentation Engineers

Citation

John S. Villarrubia and Zejun J. Ding
"Sensitivity of scanning electron microscope width measurements to model assumptions", J. Micro/Nanolith. MEMS MOEMS. 8(3), 033003 (August 17, 2009). ; http://dx.doi.org/10.1117/1.3190168


Access This Article
Sign in or Create a personal account to Buy this article ($20 for members, $25 for non-members).

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

PubMed Articles
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 Article
Sign in or Create a personal account to Buy this article ($20 for members, $25 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.