Lithography

Impact of noise sources and optical design on defect detection sensitivity in extreme ultraviolet actinic pattern inspection tool

[+] Author Affiliations
Yow-Gwo Wang, Andrew R. Neureuther

University of California, Department of Electrical Engineering and Computer Sciences, Berkeley, California, United States

Lawrence Berkeley National Laboratory, Center for X-ray Optics, Berkeley, California, United States

Patrick P. Naulleau

Lawrence Berkeley National Laboratory, Center for X-ray Optics, Berkeley, California, United States

J. Micro/Nanolith. MEMS MOEMS. 16(1), 013504 (Mar 16, 2017). doi:10.1117/1.JMM.16.1.013504
History: Received December 25, 2016; Accepted February 28, 2017
Text Size: A A A

Abstract.  We discuss the impact of various noise sources and the optical design in bright field extreme ultraviolet (EUV) actinic inspection of mask features for defects in the patterned absorber. It is shown that an optimum pixel size is needed to maximize the defect signal-to-noise ratio (SNR) to balance the trade-off in increasing signal strength with shot noise from defect signal and the background pattern intensity (mask layout image) and speckle noise from the mask blank roughness. Moreover, we consider defocus showing that the EUV mask phase effect has an asymmetric impact on pattern defect SNR’s through-focus behavior. The impact of defocus limits inspection performance based on defect SNR. Using critical defect sizes in a case study, we show the defect SNR performance of the limiting case and discuss the possibility of utilizing a nominal defocus in the inspection system to leverage the phase effect of EUV mask absorber to improve the defect SNR. A 50% improvement in defect SNR is shown to be possible by introducing a 50  nm nominal defocus into the bright field inspection system.

Figures in this Article
© 2017 Society of Photo-Optical Instrumentation Engineers

Citation

Yow-Gwo Wang ; Andrew R. Neureuther and Patrick P. Naulleau
"Impact of noise sources and optical design on defect detection sensitivity in extreme ultraviolet actinic pattern inspection tool", J. Micro/Nanolith. MEMS MOEMS. 16(1), 013504 (Mar 16, 2017). ; http://dx.doi.org/10.1117/1.JMM.16.1.013504


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

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.