17 April 2014 High speed EUV using post processing and self-aligned double patterning as a speed enhancement technique
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EUV is an ongoing industry challenge to adopt due to its current throughput limitations. The approach to improve throughput has primarily been through a significant focus on source power which has been a continuing challenge for the industry. The subject of this paper is to review and investigate the application of SADP (Self aligned double patterning) as a speed enhancing technique for EUV processing. A process with the potential of running a 16 nm self-aligned final etched pattern in less than 10mJ exposure range is proposed. Many of the current challenges with shot noise and resolution change significantly when SADP is used in conjunction with EUV. In particular, the resolution challenge for a 16nm HP final pattern type image changes to 32nm as an initial pattern requirement for the patterned CD.

With this larger CD starting point, the burden of shot noise changes significantly and the ability for higher speed resist formulations to be used is enabled. Further resist candidates that may have not met the resolution requirements for EUV can also be evaluated. This implies a completely different operational set-point for EUV resist chemistry where the relaxation of both LER and CD together combined, give the resist formulation space a new target when EUV is used as a SADP tool. Post processing mitigation of LWR is needed to attain the performance of the final 16nm half pitch target pattern to align with the industry needs.

If the original process flow at an 85W projected source power would run in the 50WPH range, then the flow proposed here would run in the <120WPH range. Although it is a double patterning technology, the proposed process still only requires a single pass through the EUV tool, This speed benefit can be used to offset the added costs associated with the double patterning process. This flow can then be shown to be an enabling approach for many EUV applications.
© (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Jerome Wandell, Jerome Wandell, Anton deVilliers, Anton deVilliers, Lior Huli, Lior Huli, Serge Biesemans, Serge Biesemans, Kathleen Nafus, Kathleen Nafus, Mike Carcasi, Mike Carcasi, Jeff Smith, Jeff Smith, Dave Hetzer, Dave Hetzer, Craig Higgins, Craig Higgins, Vinayak Rastogi, Vinayak Rastogi, Erik Verduijn, Erik Verduijn, "High speed EUV using post processing and self-aligned double patterning as a speed enhancement technique", Proc. SPIE 9048, Extreme Ultraviolet (EUV) Lithography V, 90483B (17 April 2014); doi: 10.1117/12.2048862; https://doi.org/10.1117/12.2048862

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