Self-assembly and directed self-assembly of block copolymers for nanopatterning

Block copolymers are known to spontaneously self-assemble into periodic nanoscale morphologies with characteristic feature sizes of 5-50 nm, making them attractive materials for templating and scaffolding nanostructures. In particular, the use of block copolymers in lithography processes is considered an important strategy to overcome the limitations of current photolithography tools and enables sub-20 nm features in semiconductor patterning. We are interested in understanding self-assembly and directed self-assembly processes and in developing methods to improve patterning using block copolymers.

Inorganic growth inside polymer films

Vapor-phase infiltration and growth of inorganic materials in polymers is an emerging material synthesis strategy derived from atomic layer deposition (ALD). This strategy enables the fabrication of inorganic patterns and hybrid organic-inorganic composites. We are investigating new chemistries and processes in order to develop materials and composites with novel optical and electronic properties and to control their three-dimensional structure.

Block copolymer membranes for separation processes

The supply of and access to clean water are considered one of the most pervasive problems of humanity in the 21^st century. We study and develop block copolymer and hybrid organic-inorganic membranes with nanometer sized pores for separation and water treatment processes.

Advancing 3D characterization – TEM tomography

To understand the structure-function correlation of engineered and natural nanosystems there is a growing need for three-dimensional (3D) characterization. We apply transmission electron microscopy (TEM) tomography (in TEM, STEM, at room temperature and cryo temperatures) to decipher the 3D structure of various organic, inorganic and hybrid systems. We use and develop advanced algorithms and analysis tools for image reconstruction, 3D visualization, and image analysis to probe beyond 2D imaging.

• Segal-Peretz, J. Ren, S. Xiong, G. Khaira, A. Bowen, L. E. Ocola, R. Divan, M. Doxastakis, N. J. Ferrier, J. de Pablo, P. F. Nealey, Quantitative three dimensional characterization of block copolymer directed self -assembly on combined chemical and topographical pre-patterned templates, ACS Nano, 2016, accepted.

• Ren, L. E. Ocola, R. Divan, D. A. Czaplewski, T. Segal-Peretz, S. Xiong, R. J. Kline, C. G. Arges, P. F. Nealey, Post-directed-self-assembly membrane fabrication for in-situ analysis of block copolymer structures, Nanotechnology, 2016, 27 (43), 435303. View paper

• Segal-Peretz, C. Zhou, J. Ren, T. Dazai, L. E. Ocola, R. Divan, P. F. Nealey, Three dimensional assembly in directed self-assembly of block copolymers, J. Photopolym. Sci. Technol., 2016, 29 (5), 653-657.

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• Hur, V. Thapar, A. Ramirez-Hernandez, G. S. Khaira, T. Segal-Peretz, P. A. Rincon Delgadillo, M. Muller, P. F. Nealey, J. J. de Pablo, Molecular Pathways to Defect Annihilation in Directed Self-Assembly, Proceeding of the National Academy of Science, 2015, 112 (46), 14144-14149.

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• Segal-Peretz, J. Winterstein, M. Doxastakis, A. Ramirez-Hernandez, M. Biswas, J. Ren, H. S. Suh, S. B. Darling, J. A. Liddle, J. W. Elam, J. J. de Pablo, N. Zaluzec, and P. F. Nealey, Deciphering the three-dimensional structure of block copolymers via sequential infiltration synthesis and scanning transmission electron tomography, ACS Nano, 2015, 9 (5), 5333-5347.

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• Segal-Peretz, J. Winterstein, J. Ren, M. Biswas, J. A. Liddle, L. E. Ocola, R. N. S. Divan, J. W. Elam, N. Zaluzec, and P. F. Nealey, Metrology of DSA process using TEM tomography, Proc. of SPIE, 2015, 9424, 942401U-1.

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