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Optics Express

Optics Express

  • Editor: C. Martijn de Sterke
  • Vol. 20, Iss. 23 — Nov. 5, 2012
  • pp: 25970–25978

Evidence of speckle in extreme-UV lithography

Alessandro Vaglio Pret, Roel Gronheid, Jan Engelen, Pei-Yang Yan, Michael J. Leeson, and Todd R. Younkin  »View Author Affiliations

Optics Express, Vol. 20, Issue 23, pp. 25970-25978 (2012)

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Based on reflective optics at 13.5 nm, extreme-UV lithography is the ultimate top-down technique to define structures below 22 nm but faces several challenges arising from the discrete nature of light and matter. Owing to the short wavelength, mask surface roughness plays a fundamental role in the increase of speckle pattern contrast, compromising the uniformity of the printed features. Herein, we have used a mask with engineered gradient surface roughness to illustrate the impact that speckle has on the resulting photoresist pattern. The speckle increases the photoresist roughness, but surprisingly, only when the mask surface roughness is well above existing manufacturing capabilities.

© 2012 OSA

OCIS Codes
(030.6140) Coherence and statistical optics : Speckle
(110.5220) Imaging systems : Photolithography

ToC Category:
Coherence and Statistical Optics

Original Manuscript: September 7, 2012
Revised Manuscript: October 15, 2012
Manuscript Accepted: October 17, 2012
Published: November 2, 2012

Alessandro Vaglio Pret, Roel Gronheid, Jan Engelen, Pei-Yang Yan, Michael J. Leeson, and Todd R. Younkin, "Evidence of speckle in extreme-UV lithography," Opt. Express 20, 25970-25978 (2012)

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