Articles

Speckle in optical lithography and its influence on linewidth roughness

[+] Author Affiliations
Oscar Noordman

ASML Netherlands B.V., De Run 6501, 5504DR Veldhoven, The Netherlands

Andrey Tychkov

ASML Netherlands B.V., De Run 6501, 5504DR Veldhoven, The Netherlands

Jan Baselmans

ASML Netherlands B.V., De Run 6501, 5504DR Veldhoven, The Netherlands

James Tsacoyeanes

ASML Wilton, 77 Danbury Road, Wilton, Connecticut 06897

Gary Politi

ASML Wilton, 77 Danbury Road, Wilton, Connecticut 06897

Michael Patra

Carl Zeiss SMT AG, Rudolf-Eber-Str. 2, 73447 Oberkochen, Germany

Vladan Blahnik

Carl Zeiss SMT AG, Rudolf-Eber-Str. 2, 73447 Oberkochen, Germany

Manfred Maul

Carl Zeiss SMT AG, Rudolf-Eber-Str. 2, 73447 Oberkochen, Germany

J. Micro/Nanolith. MEMS MOEMS. 8(4), 043002 (December 04, 2009). doi:10.1117/1.3256131
History: Received April 08, 2009; Revised September 02, 2009; Accepted September 16, 2009; Published December 04, 2009; Online December 04, 2009
Text Size: A A A

In recent years speckle in optical projection microlithography received increasing interest because of its potential contribution to linewidth roughness (LWR). Speckle is a light interference effect that causes the dose delivered to the reticle to be nonuniform, causing a linewidth variation of the patterns imaged in the resist. The contrast of the speckle pattern is shown to be caused by a combination of temporal and spatial coherence effects of the light. The temporal part, determined by the bandwidth of the laser light and the duration of the laser pulse, is found to be the dominant contributor to speckle in today’s ArF optical lithography. The spatial distribution of the speckle pattern depends on the intensity distribution of the light in the pupil. Consequently, the spatial frequencies of the LWR induced by speckle depend on the illumination condition, which is confirmed experimentally by exposing wafers with different amounts of speckle contrast. The experiments demonstrate that the amplitude of the LWR induced by speckle is consistent with theory and simulations. Its amplitude is small compared to other sources of LWR, but it is clearly present and should not be ignored when extending ArF optical lithography into future technology nodes.

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

Citation

Oscar Noordman ; Andrey Tychkov ; Jan Baselmans ; James Tsacoyeanes ; Gary Politi, et al.
"Speckle in optical lithography and its influence on linewidth roughness", J. Micro/Nanolith. MEMS MOEMS. 8(4), 043002 (December 04, 2009). ; http://dx.doi.org/10.1117/1.3256131


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.