Articles

Experimental verification of source-mask optimization and freeform illumination for 22-nm node static random access memory cells

[+] Author Affiliations
Joost Bekaert, Bart Laenens, Staf Verhaegen, Lieve Van Look, Darko Trivkovic, Frederic Lazzarino, Geert Vandenberghe

Imec vzw, Kapeldreef 75, 3001 Leuven, Belgium

Paul van Adrichem

ASML-BRION, 4210 Burton Drive, Santa Clara, California 95054 and ASML, De Run 6501, 5504 DR Veldhoven, The Netherlands

Robert Socha, Stephen Hsu, Hua-Yu Liu

ASML-BRION, 4210 Burton Drive, Santa Clara, California 95054

Orion Mouraille, Koen Schreel, Mircea Dusa

ASML, De Run 6501, 5504 DR Veldhoven, The Netherlands

Jörg Zimmermann, Paul Gräupner, Jens Timo Neumann

Carl Zeiss SMT AG, 73446 Oberkochen, Germany

J. Micro/Nanolith. MEMS MOEMS. 10(1), 013008 (March 10, 2011). doi:10.1117/1.3541778
History: Received April 02, 2010; Revised October 13, 2010; Accepted December 08, 2010; Published March 10, 2011; Online March 10, 2011
Text Size: A A A

The use of customized illumination modes is part of the pursuit to stretch the applicability of immersion ArF lithography. Indeed, a specific illumination source shape that is optimized for a particular design leads to enhanced imaging results. Recently, freeform illumination has become available through pixelated diffractive optical elements or through ASML’s programmable illuminator system (FlexRayTM) allowing for virtually unconstrained intensity distribution within the source pupil. In this paper, the benefit of freeform over traditional illumination is evaluated, by applying source mask co-optimization (SMO) for an aggressive use case and wafer-based verification. For a 22-nm node SRAM of 0.099 and 0.078 μm2 bit cell area, the patterning of the full contact and metal layer into a hard mask is demonstrated with the application of SMO and freeform illumination. In this work, both pixelated diffractive optical elements and FlexRay are applied. Additionally, the match between the latter two is confirmed on wafer, in terms of critical dimension and process window.

Figures in this Article
© 2011 Society of Photo-Optical Instrumentation Engineers (SPIE)

Citation

Joost Bekaert ; Bart Laenens ; Staf Verhaegen ; Lieve Van Look ; Darko Trivkovic, et al.
"Experimental verification of source-mask optimization and freeform illumination for 22-nm node static random access memory cells", J. Micro/Nanolith. MEMS MOEMS. 10(1), 013008 (March 10, 2011). ; http://dx.doi.org/10.1117/1.3541778


Tables

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.