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28 May 2004 Evaluation of the critical dimension control requirements in the ITRS using statistical simulation and error budgets
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To evaluate the ability to achieve the CD control requirements listed in the International Technology Roadmap for Semiconductors (ITRS) and to set error budget targets for focus, dose, PEB temperature uniformity, and mask CD control, statistical lithography simulation was used. A statistical model of total CD control, including the effects of intrafield and interfield error sources, was developed. The exposure tool settings such as wavelength, NA and partial coherence, focus and dose error budgets, lens aberration levels, mask type and pattern pitch values were determined for each node. Monte Carlo simulation was used to predict the CD error due to intrafield dose and focus errors. The contribution to CD error due to the mask was determined using mask CD control values in the ITRS and a calculated MEEF value at various defocus settings. The contribution to CD error due to PEB temperature variations, across wafer dose variations, and variation of aberrations and flare within the exposure field was also simulated. To meet ITRS CD control targets for 130-nm and 90-nm nodes, an alternating PSM mask is required along with a larger CD printed in resist than indicated in the ITRS. Meeting ITRS CD control requirements for 65-nm node and beyond not possible using assumptions detailed here, even with a near ideal APSM. The simulations predicted that if a relaxed pitch and a larger CD in resist were used at the 32nm node, 193nm immersion lithography in combination with a nearly ideal alternating PSM might provide CD control that is comparable to that obtainable using extreme ultraviolet lithography (EUVL).
© (2004) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Scott Daniel Hector, Sergei V. Postnikov, and Jonathan Cobb "Evaluation of the critical dimension control requirements in the ITRS using statistical simulation and error budgets", Proc. SPIE 5377, Optical Microlithography XVII, (28 May 2004);


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