29 June 1998 Application of alternating phase-shifting masks to 140-nm gate patterning: II. Mask design and manufacturing tolerances
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Proceedings Volume 3334, Optical Microlithography XI; (1998); doi: 10.1117/12.310717
Event: 23rd Annual International Symposium on Microlithography, 1998, Santa Clara, CA, United States
In this paper we present the results of experimental patterning 140 nm poly gates with double-exposure alternating phase-shifting masks (PSM) using a Nikon EX-1 (KrF, 0.42NA) stepper. We show that: systematic intrafield line width variations can be controlled within 10 nm (3(sigma) ), interfield variations across the wafer to within 6 nm (3(sigma) ), and total variation across the wafer held to within 15 nm (3(sigma) ), with a target k1 factor of k1 equals 0.237 (140 nm target gate lengths). We also present the results of studies addressing several issues related to the production application of alternating PSM's, including mask manufacturing tolerances and full chip PSM design capabilities. We show that, in comparison to conventional binary masks, alternating PSM's reduce the criticality of mask line width control and reduce the sensitivity to mask defects. Furthermore tolerance to PSM phase errors can be significantly improved by placing a chrome regulator between phase-shifters. Automatic, high-speed full chip design of alternating strong PSM is now possible.
© (1998) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Hua-Yu Liu, Linard Karklin, Yao-Ting Wang, Yagyensh C. Pati, "Application of alternating phase-shifting masks to 140-nm gate patterning: II. Mask design and manufacturing tolerances", Proc. SPIE 3334, Optical Microlithography XI, (29 June 1998); doi: 10.1117/12.310717; https://doi.org/10.1117/12.310717


Semiconducting wafers

Binary data


Phase shifts


Critical dimension metrology


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