1. Strategies for aggressive scaling of EUV multi-patterning to sub-20 nm features
- Author
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Joe Lee, Subhadeep Kal, Qiaowei Lou, Aelan Mosden, Brendan O’Brien, Naoki Shibata, Eric Liu, Luciana Meli, Chia-Yun Hsieh, Jake Kaminsky, Katie Lutker-Lee, Christopher Cole, Chi-Chun Liu, Saumya Sharma, Akiteru Ko, Angelique Raley, Jennifer Church, Lior Huli, Cody Murray, Karen Petrillo, Shan Hu, Dave Hetzer, Henan Zhang, and Ashim Dutta
- Subjects
Mandrel ,Computer science ,Extreme ultraviolet lithography ,Process optimization ,Trimming ,Surface finish ,Critical dimension ,Lithography ,Engineering physics ,Trim - Abstract
As future patterning processes reach the limit of lithographic printability, continuous innovation in mandrel trim or shrink strategies are required to reach sub-20 nm line-space patterning. Growing concerns of lithography defectivity, mask selectivity, line edge roughness (LER), line width roughness (LWR), and critical dimension uniformity (CDU) present significant challenges towards this goal. The authors compare various alternative mandrel trim strategies to highlight potential solutions and drawbacks towards enabling successful printing of mandrels used in extreme ultraviolet (EUV) multi-patterning schemes. Through this comparison, the authors demonstrate the challenges of maintaining adequate pattern transferability while keeping aspect ratio-driven line roughness and material selectivity under control. By process partitioning, the limitations of traditional lithography and etch trimming strategies are highlighted, suggesting the need for new methods of CD reduction after the pattern has been transferred. These new trimming methods offer flexibility in CD control without negatively impacting the mandrel profile and demonstrates better tunability across different material sets, allowing for evaluation of different mask and mandrel material combinations for downstream process optimization.
- Published
- 2020
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