Abstract-Large area fabrication of graphene nanoribbons by wetting transparency-assisted block copolymer lithography

• Reika Katsumata^a, 
• Maruthi Nagavalli Yogeesh^b, 
• Helen Wong^a, 
• Sunshine X. Zhou^a, 
• Stephen M. Sirard^c,
• Tao Huang^d, 
• Richard D. Piner^e, f, 
• Zilong Wu^f, 
• Wei Li^b, f, 
• Alvin L. Lee^b, 
• Matthew Carlson^a, 
• Michael Maher^g,
• Deji Akinwande^b, f, 
• Christopher J. Ellison^a, e, 

• ^a McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, TX 78712, United States
• ^b Microelectronics Research Center, The University of Texas at Austin, Austin, TX 78758, United States
• ^c Lam Research Corporation, 12345 North Lamar Boulevard, Austin, TX 78753, United States
• ^d Department of Organic and Polymeric Materials, Tokyo Institute of Technology, Tokyo 152-8552, Japan
• ^e Department of Mechanical Engineering, The University of Texas at Austin, TX 78712, United States
• ^f Materials Science & Engineering Program and Texas Materials Institute, The University of Texas at Austin, Austin, TX 78712, United States
• ^g Department of Chemistry, The University of Texas at Austin, Austin, TX 78712, United States
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• http://www.sciencedirect.com/science/article/pii/S003238611631120X
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Patterning graphene into nanoribbons (graphene nanoribbons, GNR) allows for tunability in the emerging fields of plasmonic devices in the mid-infrared and terahertz regime. However, the fabrication processes of GNR arrays for plasmonic devices often include a low-throughput electron beam lithography step that cannot be easily scaled to large areas. In this study, we developed a GNR fabrication method using block copolymer (BCP) lithography that takes advantage of the wetting transparency of graphene. One major advantage of this method is that the self-assembled domains of the polystyrene-block-poly(methyl methacrylate) BCP are oriented perpendicularly directly on top of the graphene where they can later serve as an etch mask. Large area (cm² scale, 3 μm × 3 μm defect-free area) 13–51 nm wide GNR arrays were successfully fabricated using this scalable protocol. This wetting transparency-assisted GNR fabrication method could be useful for high-throughput production of various plasmonic devices, including biosensors, and photodetectors.