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

Joost P. M. Bekaert; Bart Laenens; Staf Verhaegen; Lieve Van Look; Darko Trivkovic; Frederic Lazzarino; Geert Vandenberghe; Paul van Adrichem; Robert J. Socha; Stephen Hsu; Hua-yu Liu; Orion Mouraille; Koen Schreel; Mircea V. Dusa; Jörg Zimmermann; Paul Gräupner; Jens T. Neumann

doi:10.1117/1.3541778

1 January 2011 Experimental verification of source-mask optimization and freeform illumination for 22-nm node static random access memory cells

Joost P. M. Bekaert, Bart Laenens, Staf Verhaegen, Lieve Van Look, Darko Trivkovic, Frederic Lazzarino, Geert Vandenberghe, Paul van Adrichem, Robert J. Socha, Stephen Hsu, Hua-yu Liu, Orion Mouraille, Koen Schreel, Mircea V. Dusa, Jörg Zimmermann, Paul Gräupner, Jens T. Neumann

Author Affiliations +

Journal of Micro/Nanolithography, MEMS, and MOEMS, Vol. 10, Issue 1, 013008 (January 2011). https://doi.org/10.1117/1.3541778

Abstract

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 (FlexRay^TM) 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.

©(2011) Society of Photo-Optical Instrumentation Engineers (SPIE)

Citation Download Citation

Joost P. M. Bekaert, Bart Laenens, Staf Verhaegen, Lieve Van Look, Darko Trivkovic, Frederic Lazzarino, Geert Vandenberghe, Paul van Adrichem, Robert J. Socha, Stephen Hsu, Hua-yu Liu, Orion Mouraille, Koen Schreel, Mircea V. Dusa, Jörg Zimmermann, Paul Gräupner, and Jens T. Neumann "Experimental verification of source-mask optimization and freeform illumination for 22-nm node static random access memory cells," Journal of Micro/Nanolithography, MEMS, and MOEMS 10(1), 013008 (1 January 2011). https://doi.org/10.1117/1.3541778

Published: 1 January 2011

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available