1
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Patel BB, Feng H, Loo WS, Snyder CR, Eom C, Murphy J, Sunday DF, Nealey PF, DeLongchamp DM. Self-Assembly of Hierarchical High-χ Fluorinated Block Copolymers with an Orthogonal Smectic-within-Lamellae 3 nm Sublattice and Vertical Surface Orientation. ACS NANO 2024; 18:11311-11322. [PMID: 38623826 DOI: 10.1021/acsnano.4c00664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/17/2024]
Abstract
Hierarchical structure-within-structure assemblies offer a route toward increasingly complex and multifunctional materials while pushing the limits of block copolymer self-assembly. We present a detailed study of the self-assembly of a series of fluorinated high-χ block copolymers (BCPs) prepared via postmodification of a single poly(styrene)-block-poly(glycidyl methacrylate) (S-b-G) parent polymer with the fluorinated alkylthiol pendent groups containing 1, 6, or 8 fluorinated carbons (termed trifluoro-ethanethiol (TFET), perfluoro-octylthiol (PFOT), and perfluoro-decylthiol (PFDT), respectively). Bulk X-ray scattering of thermally annealed samples demonstrates hierarchical molecular assembly with phase separation between the two blocks and within the fluorinated block. The degree of ordering within the fluorinated block is highly sensitive to synthetic variation; a lamellar sublattice was formed for S-b-GPFOT and S-b-GPFDT. Thermal analyses of S-b-GPFOT reveal that the fluorinated block exhibits liquid crystal-like ordering. The complex thin-film self-assembly behavior of an S-b-GPFOT polymer was investigated using real-space (atomic force microscopy and scanning electron microscopy) and reciprocal-space (resonant soft X-ray scattering (RSoXS), grazing incidence small- and wide-angle scattering) measurements. After thermal annealing in nitrogen or vacuum, films thicker than 1.5 times the primary lattice spacing exhibit a 90-degree grain boundary, exposing a thin layer of vertical lamellae at the free interface, while exhibiting horizontal lamellae on the preferential (polystyrene brush) substrate. RSoXS measurements reveal the near-perfect orthogonality between the primary and sublattice orientations, demonstrating hierarchical patterning at the nanoscale.
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Affiliation(s)
- Bijal B Patel
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Hongbo Feng
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
| | - Whitney S Loo
- Department of Chemical and Biological Engineering, University of Wisconsin─Madison, Madison, Wisconsin 53706, United States
| | - Chad R Snyder
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Christopher Eom
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
| | - Julia Murphy
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Daniel F Sunday
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Paul F Nealey
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
| | - Dean M DeLongchamp
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
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2
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Weisbord I, Segal-Peretz T. Revealing the 3D Structure of Block Copolymers with Electron Microscopy: Current Status and Future Directions. ACS APPLIED MATERIALS & INTERFACES 2023; 15:58003-58022. [PMID: 37338172 DOI: 10.1021/acsami.3c02956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2023]
Abstract
Block copolymers (BCPs) are considered model systems for understanding and utilizing self-assembly in soft matter. Their tunable nanometric structure and composition enable comprehensive studies of self-assembly processes as well as make them relevant materials in diverse applications. A key step in developing and controlling BCP nanostructures is a full understanding of their three-dimensional (3D) structure and how this structure is affected by the BCP chemistry, confinement, boundary conditions, and the self-assembly evolution and dynamics. Electron microscopy (EM) is a leading method in BCP 3D characterization owing to its high resolution in imaging nanosized structures. Here we discuss the two main 3D EM methods: namely, transmission EM tomography and slice and view scanning EM tomography. We present each method's principles, examine their strengths and weaknesses, and discuss ways researchers have devised to overcome some of the challenges in BCP 3D characterization with EM- from specimen preparation to imaging radiation-sensitive materials. Importantly, we review current and new cutting-edge EM methods such as direct electron detectors, energy dispersive X-ray spectroscopy of soft matter, high temporal rate imaging, and single-particle analysis that have great potential for expanding the BCP understanding through EM in the future.
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Affiliation(s)
- Inbal Weisbord
- Chemical Engineering Department, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Tamar Segal-Peretz
- Chemical Engineering Department, Technion-Israel Institute of Technology, Haifa 3200003, Israel
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3
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Mukherjee S, Streit JK, Gann E, Saurabh K, Sunday DF, Krishnamurthy A, Ganapathysubramanian B, Richter LJ, Vaia RA, DeLongchamp DM. Polarized X-ray scattering measures molecular orientation in polymer-grafted nanoparticles. Nat Commun 2021; 12:4896. [PMID: 34385430 PMCID: PMC8361200 DOI: 10.1038/s41467-021-25176-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 07/08/2021] [Indexed: 11/08/2022] Open
Abstract
Polymer chains are attached to nanoparticle surfaces for many purposes, including altering solubility, influencing aggregation, dispersion, and even tailoring immune responses in drug delivery. The most unique structural motif of polymer-grafted nanoparticles (PGNs) is the high-density region in the corona where polymer chains are stretched under significant confinement, but orientation of these chains has never been measured because conventional nanoscale-resolved measurements lack sensitivity to polymer orientation in amorphous regions. Here, we directly measure local chain orientation in polystyrene grafted gold nanoparticles using polarized resonant soft X-ray scattering (P-RSoXS). Using a computational scattering pattern simulation approach, we measure the thickness of the anisotropic region of the corona and extent of chain orientation within it. These results demonstrate the power of P-RSoXS to discover and quantify orientational aspects of structure in amorphous soft materials and provide a framework for applying this emerging technique to more complex, chemically heterogeneous systems in the future.
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Affiliation(s)
- Subhrangsu Mukherjee
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA
| | - Jason K Streit
- Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright Patterson Air Force Base, OH, USA
- UES, Inc., Dayton, OH, USA
| | - Eliot Gann
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA
| | - Kumar Saurabh
- Department of Mechanical Engineering, Iowa State University, Ames, IA, USA
| | - Daniel F Sunday
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA
| | | | | | - Lee J Richter
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA
| | - Richard A Vaia
- Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright Patterson Air Force Base, OH, USA
| | - Dean M DeLongchamp
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA.
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4
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Shiohara A, Prieto-Simon B, Voelcker NH. Porous polymeric membranes: fabrication techniques and biomedical applications. J Mater Chem B 2021; 9:2129-2154. [PMID: 33283821 DOI: 10.1039/d0tb01727b] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Porous polymeric membranes have shown great potential in biological and biomedical applications such as tissue engineering, bioseparation, and biosensing, due to their structural flexibility, versatile surface chemistry, and biocompatibility. This review outlines the advantages and limitations of the fabrication techniques commonly used to produce porous polymeric membranes, with especial focus on those featuring nano/submicron scale pores, which include track etching, nanoimprinting, block-copolymer self-assembly, and electrospinning. Recent advances in membrane technology have been key to facilitate precise control of pore size, shape, density and surface properties. The review provides a critical overview of the main biological and biomedical applications of these porous polymeric membranes, especially focusing on drug delivery, tissue engineering, biosensing, and bioseparation. The effect of the membrane material and pore morphology on the role of the membranes for each specific application as well as the specific fabrication challenges, and future prospects of these membranes are thoroughly discussed.
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Affiliation(s)
- Amane Shiohara
- Drug Delivery, Deposition, and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia. and Commonwealth Scientific and Industrial Research Organisation (CSIRO), Clayton, Victoria 3168, Australia and Melbourne Centre of Nanofabrication, Victorian Node of the Australian National Fabrication Facility, Clayton, Victoria 3168, Australia
| | - Beatriz Prieto-Simon
- Drug Delivery, Deposition, and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia. and Department of Electronic Engineering, Universitat Rovira i Virgili, 43007 Tarragona, Spain and ICREA, Pg. Lluís Companys 23, 08010 Barcelona, Spain
| | - Nicolas H Voelcker
- Drug Delivery, Deposition, and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia. and Commonwealth Scientific and Industrial Research Organisation (CSIRO), Clayton, Victoria 3168, Australia and Melbourne Centre of Nanofabrication, Victorian Node of the Australian National Fabrication Facility, Clayton, Victoria 3168, Australia
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5
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Sunday DF, Dolejsi M, Chang AB, Richter LJ, Li R, Kline RJ, Nealey PF, Grubbs RH. Confinement and Processing Can Alter the Morphology and Periodicity of Bottlebrush Block Copolymers in Thin Films. ACS NANO 2020; 14:17476-17486. [PMID: 33225683 DOI: 10.1021/acsnano.0c07777] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Bottlebrush block copolymers (BBCPs) are intriguing architectural variations on linear BCPs with highly tunable structure. Confinement can have a significant impact on polymer assembly, giving rise to changes in morphology, assembly kinetics, and properties like the glass transition. Given that confinement leads to significant changes in the persistence length of bottlebrush homopolymers, it is reasonable to expect that BBCPs will see significant changes in their structure and periodicity relative to the bulk morphology. Understanding how confinement influences assembly will be important for designing BBCPs for thin film applications including membranes, integrated photonic structures, and potentially BCP lithography. In order to study the effects of confinement on BBCP conformation and morphology, a blade coating was used to prepare films with continuous variation in film thickness. Unlike thin films of linear BCPs, islands/holes were not observed, and instead mixtures of parallel and perpendicular morphologies emerge after annealing. The lamellar periodicity (L0) of the morphologies is found to be thickness dependent, increasing L0 with decreasing film thickness for blade coated films. Films coated out of tetrahydrofuran (THF) resulted in a single well-defined lamellar periodicity, verified through atomic force microscopy (AFM) and grazing incidence small-angle X-ray scattering (GISAXS), which increases dramatically from the bulk value (30.6 nm) and continues to increase as the film thickness decreases. The largest observed L0 was 65.5 nm, and this closely approaches the estimated upper limit of 67 nm corresponding to a fully extended backbone in a bilayer arrangement. Films coated out of propylene glycol methyl ether acetate (PGMEA) resulted in a mixture of perpendicular lamellae and a smaller, likely cylindrical morphology. The lamellar portion of the film shows the same thickness dependence as the lamellae observed in the THF coated films. The scaling of the lamellar L0 with respect to film thickness follows predictions for confined semiflexible polymers with weak excluded volume interactions and can be related to models for confinement of DNA. Spin coated films shows the same reduction in periodicity, although at very different film thicknesses. This result suggests that the material has shallow free-energy barriers to transitioning between different L0 and morphologies, a property that could be taken advantage of for patterning diverse structures with a single material.
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Affiliation(s)
- Daniel F Sunday
- Materials Science and Engineering Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States
| | - Moshe Dolejsi
- Institute for Molecular Engineering, University of Chicago, 5801 S Ellis Ave, Chicago, Illinois 60637, United States
| | - Alice B Chang
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Lee J Richter
- Materials Science and Engineering Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States
| | - Ruipeng Li
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - R Joseph Kline
- Materials Science and Engineering Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States
| | - Paul F Nealey
- Institute for Molecular Engineering, University of Chicago, 5801 S Ellis Ave, Chicago, Illinois 60637, United States
| | - Robert H Grubbs
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
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6
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He X, Waldman RZ, Mandia DJ, Jeon N, Zaluzec NJ, Borkiewicz OJ, Ruett U, Darling SB, Martinson ABF, Tiede DM. Resolving the Atomic Structure of Sequential Infiltration Synthesis Derived Inorganic Clusters. ACS NANO 2020; 14:14846-14860. [PMID: 33170644 DOI: 10.1021/acsnano.0c03848] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Sequential infiltration synthesis (SIS) is a route to the precision deposition of inorganic solids in analogy to atomic layer deposition but occurs within (vs upon) a soft material template. SIS has enabled exquisite nanoscale morphological complexity in various oxides through selective nucleation in block copolymers templates. However, the earliest stages of SIS growth remain unresolved, including the atomic structure of nuclei and the evolution of local coordination environments, before and after polymer template removal. We employed In K-edge extended X-ray absorption fine structure and atomic pair distribution function analysis of high-energy X-ray scattering to unravel (1) the structural evolution of InOxHy clusters inside a poly(methyl methacrylate) (PMMA) host matrix and (2) the formation of porous In2O3 solids (obtained after annealing) as a function of SIS cycle number. Early SIS cycles result in InOxHy cluster growth with high aspect ratio, followed by the formation of a three-dimensional network with additional SIS cycles. That the atomic structures of the InOxHy clusters can be modeled as multinuclear clusters with bonding patterns related to those in In2O3 and In(OH)3 crystal structures suggests that SIS may be an efficient route to 3D arrays of discrete-atom-number clusters. Annealing the mixed inorganic/polymer films in air removes the PMMA template and consolidates the as-grown clusters into cubic In2O3 nanocrystals with structural details that also depend on SIS cycle number.
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Affiliation(s)
| | - Ruben Z Waldman
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
| | | | | | | | | | | | - Seth B Darling
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
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7
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Ren J, Segal-Peretz T, Zhou C, Craig GSW, Nealey PF. Three-dimensional superlattice engineering with block copolymer epitaxy. SCIENCE ADVANCES 2020; 6:eaaz0002. [PMID: 32582846 PMCID: PMC7292617 DOI: 10.1126/sciadv.aaz0002] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Accepted: 05/01/2020] [Indexed: 05/26/2023]
Abstract
Three-dimensional (3D) structures at the nanometer length scale play a crucial role in modern devices, but their fabrication using traditional top-down approaches is complex and expensive. Analogous to atomic lattices, block copolymers (BCPs) spontaneously form a rich variety of 3D nanostructures and have the potential to substantially simplify 3D nanofabrication. Here, we show that the 3D superlattice formed by BCP micelles can be controlled by lithographically defined 2D templates matching a crystallographic plane in the 3D superlattice. Using scanning transmission electron microscopy tomography, we demonstrate precise control over the lattice symmetry and orientation. Excellent ordering and substrate registration can be achieved, propagating through 284-nanometer-thick films. BCP epitaxy also showed exceptional lattice tunability, with a continuous Bain transformation from a body-centered cubic to a face-centered cubic lattice. Lattice stability was mediated by molecular packing frustration, and surface-induced lattice reconstruction was observed, leading to the formation of a unique honeycomb lattice.
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Affiliation(s)
- Jiaxing Ren
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
| | - Tamar Segal-Peretz
- Department of Chemical Engineering, Technion–Israel Institute of Technology, Haifa 32000 Israel
| | - Chun Zhou
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
| | - Gordon S. W. Craig
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
| | - Paul F. Nealey
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
- Materials Science Division, Argonne National Laboratory, Lemont, IL 60439, USA
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8
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Jin HM, Li X, Dolan JA, Kline RJ, Martínez-González JA, Ren J, Zhou C, de Pablo JJ, Nealey PF. Soft crystal martensites: An in situ resonant soft x-ray scattering study of a liquid crystal martensitic transformation. SCIENCE ADVANCES 2020; 6:eaay5986. [PMID: 32258402 PMCID: PMC7101220 DOI: 10.1126/sciadv.aay5986] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 01/03/2020] [Indexed: 05/15/2023]
Abstract
Liquid crystal blue phases (BPs) are three-dimensional soft crystals with unit cell sizes orders of magnitude larger than those of classic, atomic crystals. The directed self-assembly of BPs on chemically patterned surfaces uniquely enables detailed in situ resonant soft x-ray scattering measurements of martensitic phase transformations in these systems. The formation of twin lamellae is explicitly identified during the BPII-to-BPI transformation, further corroborating the martensitic nature of this transformation and broadening the analogy between soft and atomic crystal diffusionless phase transformations to include their strain-release mechanisms.
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Affiliation(s)
- Hyeong Min Jin
- Pritzker School of Molecular Engineering, The University of Chicago, Chicago, IL 60637, USA
- Neutron Science Center, Korea Atomic Energy Research Institute (KAERI), Daejeon 34057, Republic of Korea
| | - Xiao Li
- Pritzker School of Molecular Engineering, The University of Chicago, Chicago, IL 60637, USA
- Department of Materials Science and Engineering, University of North Texas, Denton, TX 76203, USA
| | - James A. Dolan
- Pritzker School of Molecular Engineering, The University of Chicago, Chicago, IL 60637, USA
- Center for Molecular Engineering, Argonne National Laboratory, Lemont, IL 60439, USA
| | - R. Joseph Kline
- Materials Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - José A. Martínez-González
- Facultad de Ciencias, Universidad Autónoma de San Luis Potosí, Av. Parque Chapultepec 1570, San Luis Potosí 78295, SLP, México
| | - Jiaxing Ren
- Pritzker School of Molecular Engineering, The University of Chicago, Chicago, IL 60637, USA
| | - Chun Zhou
- Pritzker School of Molecular Engineering, The University of Chicago, Chicago, IL 60637, USA
| | - Juan J. de Pablo
- Pritzker School of Molecular Engineering, The University of Chicago, Chicago, IL 60637, USA
- Center for Molecular Engineering, Argonne National Laboratory, Lemont, IL 60439, USA
| | - Paul F. Nealey
- Pritzker School of Molecular Engineering, The University of Chicago, Chicago, IL 60637, USA
- Center for Molecular Engineering, Argonne National Laboratory, Lemont, IL 60439, USA
- Corresponding author.
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9
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Waldman RZ, Mandia DJ, Yanguas-Gil A, Martinson ABF, Elam JW, Darling SB. The chemical physics of sequential infiltration synthesis-A thermodynamic and kinetic perspective. J Chem Phys 2019; 151:190901. [PMID: 31757164 DOI: 10.1063/1.5128108] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Sequential infiltration synthesis (SIS) is an emerging materials growth method by which inorganic metal oxides are nucleated and grown within the free volume of polymers in association with chemical functional groups in the polymer. SIS enables the growth of novel polymer-inorganic hybrid materials, porous inorganic materials, and spatially templated nanoscale devices of relevance to a host of technological applications. Although SIS borrows from the precursors and equipment of atomic layer deposition (ALD), the chemistry and physics of SIS differ in important ways. These differences arise from the permeable three-dimensional distribution of functional groups in polymers in SIS, which contrast to the typically impermeable two-dimensional distribution of active sites on solid surfaces in ALD. In SIS, metal-organic vapor-phase precursors dissolve and diffuse into polymers and interact with these functional groups through reversible complex formation and/or irreversible chemical reactions. In this perspective, we describe the thermodynamics and kinetics of SIS and attempt to disentangle the tightly coupled physical and chemical processes that underlie this method. We discuss the various experimental, computational, and theoretical efforts that provide insight into SIS mechanisms and identify approaches that may fill out current gaps in knowledge and expand the utilization of SIS.
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Affiliation(s)
- Ruben Z Waldman
- Pritzker School of Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, USA
| | - David J Mandia
- Applied Materials Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Angel Yanguas-Gil
- Applied Materials Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Alex B F Martinson
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Lemont, Illinois 60439, USA
| | - Jeffrey W Elam
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Lemont, Illinois 60439, USA
| | - Seth B Darling
- Pritzker School of Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, USA
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10
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Ren J, Zhou C, Chen X, Dolejsi M, Craig GSW, Rincon Delgadillo PA, Segal-Peretz T, Nealey PF. Engineering the Kinetics of Directed Self-Assembly of Block Copolymers toward Fast and Defect-Free Assembly. ACS APPLIED MATERIALS & INTERFACES 2018; 10:23414-23423. [PMID: 29878751 DOI: 10.1021/acsami.8b05247] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Directed self-assembly (DSA) of block copolymers (BCPs) can achieve perfectly aligned structures at thermodynamic equilibrium, but the self-assembling morphology can become kinetically trapped in defective states. Understanding and optimizing the kinetic pathway toward domain alignment is crucial for enhancing process throughput and lowering defectivity to levels required for semiconductor manufacturing, but there is a dearth of experimental, three-dimensional studies of the kinetic pathways in DSA. Here, we combined arrested annealing and TEM tomography to probe the kinetics and structural evolution in the chemoepitaxy DSA of PS- b-PMMA with density multiplication. During the initial stages of annealing, BCP domains developed independently at first, with aligned structures at the template interface and randomly oriented domains at the top surface. As the grains coarsened, the assembly became cooperative throughout the film thickness, and a metastable stitch morphology was formed, representing a kinetic barrier. The stitch morphology had a three-dimensional structure consisting of both perpendicular and parallel lamellae. On the basis of the mechanistic information, we studied the effect of key design parameters on the kinetics and evolution of structures in DSA. Three types of structural evolutions were observed at different film thicknesses: (1) immediate alignment and fast assembly when thickness < L0 ( L0 = BCP natural periodicity); (2) formation of stitch morphology for 1.25-1.45 L0; (3) fingerprint formation when thickness >1.64 L0. We found that the DSA kinetics can be significantly improved by avoiding the formation of the metastable stitch morphology. Increasing template topography also enhanced the kinetics by increasing the PMMA guiding surface area. A combination of 0.75 L0 BCP thickness and 0.50 L0 template topography achieved perfect alignment over 100 times faster than the baseline process. This research demonstrates that an improved understanding of the evolution of structures during DSA can significantly improve the DSA process.
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Affiliation(s)
- Jiaxing Ren
- Institute for Molecular Engineering , University of Chicago , Chicago , Illinois 60637 , United States
| | - Chun Zhou
- Institute for Molecular Engineering , University of Chicago , Chicago , Illinois 60637 , United States
| | - Xuanxuan Chen
- Institute for Molecular Engineering , University of Chicago , Chicago , Illinois 60637 , United States
| | - Moshe Dolejsi
- Institute for Molecular Engineering , University of Chicago , Chicago , Illinois 60637 , United States
| | - Gordon S W Craig
- Institute for Molecular Engineering , University of Chicago , Chicago , Illinois 60637 , United States
| | | | - Tamar Segal-Peretz
- Department of Chemical Engineering , Technion - Institute of Technology , Haifa 3200003 , Israel
| | - Paul F Nealey
- Institute for Molecular Engineering , University of Chicago , Chicago , Illinois 60637 , United States
- Materials Science Division , Argonne National Laboratory , Lemont , Illinois 60439 , United States
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11
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Khaira G, Doxastakis M, Bowen A, Ren J, Suh HS, Segal-Peretz T, Chen X, Zhou C, Hannon AF, Ferrier NJ, Vishwanath V, Sunday DF, Gronheid R, Kline RJ, de Pablo JJ, Nealey PF. Derivation of Multiple Covarying Material and Process Parameters Using Physics-Based Modeling of X-ray Data. Macromolecules 2017. [DOI: 10.1021/acs.macromol.7b00691] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Gurdaman Khaira
- Mentor: A Siemens Business, Wilsonville, Oregon 97070, United States
| | - Manolis Doxastakis
- Department
of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Alec Bowen
- Institute for Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, United States
| | - Jiaxing Ren
- Institute for Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, United States
| | - Hyo Seon Suh
- Institute for Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, United States
| | - Tamar Segal-Peretz
- Department
of Chemical Engineering, Technion - Israel Institute of Technology, Haifa 32000, Israel
| | - Xuanxuan Chen
- Institute for Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, United States
| | - Chun Zhou
- Institute for Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, United States
| | - Adam F. Hannon
- Material
Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | | | | | - Daniel F. Sunday
- Material
Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | | | - R. Joseph Kline
- Material
Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Juan J. de Pablo
- Institute for Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, United States
- Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Paul F. Nealey
- Institute for Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, United States
- Argonne National Laboratory, Argonne, Illinois 60439, United States
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12
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Sunday DF, Ren J, Liman CD, Williamson LD, Gronheid R, Nealey PF, Kline RJ. Characterizing Patterned Block Copolymer Thin Films with Soft X-rays. ACS APPLIED MATERIALS & INTERFACES 2017; 9:31325-31334. [PMID: 28541658 DOI: 10.1021/acsami.7b02791] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
The directed self-assembly (DSA) of block copolymers (BCPs) is a potential solution for patterning critical features for integrated circuits at future technology nodes. For this process to be implemented, there needs to be a better understanding of how the template guides the assembly and induces subsurface changes in the lamellar structure. Using a rotational transmission X-ray scattering measurement coupled with soft X-rays to improve contrast between polymer components, the impact of the ratio of the guiding stripe width (W) to the BCP pitch (L0) was investigated. For W/L0 < 1, continuous vertical lamella were observed, with some fluctuations in the interface profile near the template that smoothed out further up the structure. Near W/L0 ≈ 1.5, the arrangement of the lamella shifted, moving from polystyrene centered on the guiding stripe to poly(methyl methacrylate) centered on the guiding stripe.
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Affiliation(s)
- Daniel F Sunday
- National Institute of Standards and Technology , Gaithersburg, Maryland 20899, United States
| | - Jiaxing Ren
- Institute for Molecular Engineering, University of Chicago , Chicago, Illinois 60637, United States
| | - Christopher D Liman
- National Institute of Standards and Technology , Gaithersburg, Maryland 20899, United States
| | - Lance D Williamson
- Institute for Molecular Engineering, University of Chicago , Chicago, Illinois 60637, United States
| | | | - Paul F Nealey
- Institute for Molecular Engineering, University of Chicago , Chicago, Illinois 60637, United States
| | - R Joseph Kline
- National Institute of Standards and Technology , Gaithersburg, Maryland 20899, United States
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Segal-Peretz T, Ren J, Xiong S, Khaira G, Bowen A, Ocola LE, Divan R, Doxastakis M, Ferrier NJ, de Pablo J, Nealey PF. Quantitative Three-Dimensional Characterization of Block Copolymer Directed Self-Assembly on Combined Chemical and Topographical Prepatterned Templates. ACS NANO 2017; 11:1307-1319. [PMID: 28005329 DOI: 10.1021/acsnano.6b05657] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Characterization of the three-dimensional (3D) structure in directed self-assembly (DSA) of block copolymers is crucial for understanding the complex relationships between the guiding template and the resulting polymer structure so DSA could be successfully implemented for advanced lithography applications. Here, we combined scanning transmission electron microscopy (STEM) tomography and coarse-grain simulations to probe the 3D structure of P2VP-b-PS-b-P2VP assembled on prepatterned templates using solvent vapor annealing. The templates consisted of nonpreferential background and raised guiding stripes that had PS-preferential top surfaces and P2VP-preferential sidewalls. The full 3D characterization allowed us to quantify the shape of the polymer domains and the interface between domains as a function of depth in the film and template geometry and offered important insights that were not accessible with 2D metrology. Sidewall guiding was advantageous in promoting the alignment and lowering the roughness of the P2VP domains over the sidewalls, but incommensurate confinement from the increased topography could cause roughness and intermittent dislocations in domains over the background region at the bottom of the film. The 3D characterization of bridge structures between domains over the background and breaks within domains on guiding lines sheds light on possible origins of common DSA defects. The positional fluctuations of the PS/P2VP interface between domains showed a depth-dependent behavior, with high levels of fluctuations near both the free surface of the film and the substrate and lower fluctuation levels in the middle of the film. This research demonstrates how 3D characterization offers a better understanding of DSA processes, leading to better design and fabrication of directing templates.
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Affiliation(s)
- Tamar Segal-Peretz
- Institute for Molecular Engineering, University of Chicago , 5640 South Ellis Avenue, Chicago, Illinois 60637, United States
- Department of Chemical Engineering, Technion - Institute of Technology , Haifa 3200003, Israel
| | - Jiaxing Ren
- Institute for Molecular Engineering, University of Chicago , 5640 South Ellis Avenue, Chicago, Illinois 60637, United States
| | - Shisheng Xiong
- Institute for Molecular Engineering, University of Chicago , 5640 South Ellis Avenue, Chicago, Illinois 60637, United States
| | - Gurdaman Khaira
- Institute for Molecular Engineering, University of Chicago , 5640 South Ellis Avenue, Chicago, Illinois 60637, United States
| | - Alec Bowen
- Institute for Molecular Engineering, University of Chicago , 5640 South Ellis Avenue, Chicago, Illinois 60637, United States
| | | | | | - Manolis Doxastakis
- Institute for Molecular Engineering, University of Chicago , 5640 South Ellis Avenue, Chicago, Illinois 60637, United States
| | - Nicola J Ferrier
- Institute for Molecular Engineering, University of Chicago , 5640 South Ellis Avenue, Chicago, Illinois 60637, United States
| | - Juan de Pablo
- Institute for Molecular Engineering, University of Chicago , 5640 South Ellis Avenue, Chicago, Illinois 60637, United States
| | - Paul F Nealey
- Institute for Molecular Engineering, University of Chicago , 5640 South Ellis Avenue, Chicago, Illinois 60637, United States
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