7 June 2010 Design compliant source mask optimization (SMO)
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Proceedings Volume 7748, Photomask and Next-Generation Lithography Mask Technology XVII; 77480T (2010) https://doi.org/10.1117/12.865781
Event: Photomask and NGL Mask Technology XVII, 2010, Yokohama, Japan
In this paper the co-optimization of the source, mask, and design is discussed. In particular the printing of the pdBRIX logic templates and SRAM cell is investigated through Tachyon SMO for the contact and metal 1 layer. Both the SRAM and pdBRIX logic templates were designed for the 22nm logic node with a 40nm half-pitch. The source and mask were optimized for an ASML /1950 at maximum NA of 1.35 and with FlexRay illumination. The use of pdBRIX logic templates are designed on a regular fabric consistent with the SRAM to enable process window improvement as well as faster convergence of SMO with the desired effect of reducing the lithographic process development time. To this end, various feedback loops in the design and lithography co-optimization are considered. All these feedback loops were eliminated by studying both the SRAM layout with random logic created from pdBRIX templates. One feedback loop of insufficient process window (PW) for the contact layer is corrected by using a bright field mask and negative process which increases the PW area by three times. The improper coloring of a contact hole layer through double patterning is found through SMO, and corrected by modifying the color scheme. A redesign of the SRAM while preserving the area of the SRAM cell is suggested by SMO in which the redesign improves the PW by 19.5%. Finally, we discuss the improvement in PW for simultaneous SMO on pdBRIX logic and SRAM.
© (2010) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Robert Socha, Tejas Jhaveri, Mircea Dusa, Xiaofeng Liu, Luoqi Chen, Stephen Hsu, Zhipan Li, Andrzej J. Strojwas, "Design compliant source mask optimization (SMO)", Proc. SPIE 7748, Photomask and Next-Generation Lithography Mask Technology XVII, 77480T (7 June 2010); doi: 10.1117/12.865781; https://doi.org/10.1117/12.865781

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