1
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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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2
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Loo WS, Feng H, Ferron TJ, Ruiz R, Sunday DF, Nealey PF. Determining Structure and Thermodynamics of A- b-(B- r-C) Copolymers. ACS Macro Lett 2023; 12:118-124. [PMID: 36630274 DOI: 10.1021/acsmacrolett.2c00645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The self-assembly of block copolymers (BCPs) is dictated by their segregation strength, χN, and while there are well-developed methods for determining χ in the weak and strong segregation regimes, it is challenging to accurately measure χ of copolymers with intermediate segregation strengths, especially when copolymers have inaccessible order-disorder transition temperatures. χeff is often approximated by using strong segregation theory (SST), but utilizing these values to estimate the interface width (wm) of BCPs in the intermediate segregation regime often results in predictions that deviate significantly from measured values. Therefore, we propose using the extent of mixing, quantified as the normalized interface width wm/L0, where L0 is the block copolymer pitch, as a thermodynamic parameter. We experimentally measure wm and L0 for a series of lamellar A-b-(B-r-C) copolymers via resonant soft X-ray reflectivity and extract values of χeffN based on previous data collected for A-b-B copolymers. The composition profiles measured via reflectivity match the extracted χeffN values, while those calculated with SST predict much more mixed composition profiles. The extracted χeff values agreed quantitatively between copolymers of different molecular weights. We believe that this methodology will be well-suited for block copolymers used in lithographic applications due to their inaccessible order-disorder transition temperatures, intermediate values of χN, and the importance of wm for line edge roughness metrics.
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Affiliation(s)
- Whitney S Loo
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois60637, United States
| | - Hongbo Feng
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois60637, United States
| | - Thomas J Ferron
- Material Sciences and Engineering Division, National Institute of Standards and Technology, Gaithersburg, Maryland20899, United States
| | - Ricardo Ruiz
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California94720, United States
| | - Daniel F Sunday
- Material Sciences and Engineering Division, National Institute of Standards and Technology, Gaithersburg, Maryland20899, United States
| | - Paul F Nealey
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois60637, United States
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3
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Feng H, Dolejsi M, Zhu N, Yim S, Loo W, Ma P, Zhou C, Craig GSW, Chen W, Wan L, Ruiz R, de Pablo JJ, Rowan SJ, Nealey PF. Optimized design of block copolymers with covarying properties for nanolithography. NATURE MATERIALS 2022; 21:1426-1433. [PMID: 36357686 DOI: 10.1038/s41563-022-01392-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 09/30/2022] [Indexed: 06/16/2023]
Abstract
The ability to impart multiple covarying properties into a single material represents a grand challenge in manufacturing. In the design of block copolymers (BCPs) for directed self-assembly and nanolithography, materials often balance orthogonal properties to meet constraints related to processing, structure and defectivity. Although iterative synthesis strategies deliver BCPs with attractive properties, identifying materials with all the required attributes has been difficult. Here we report a high-throughput synthesis and characterization platform for the discovery and optimization of BCPs with A-block-(B-random-C) architectures for lithographic patterning in semiconductor manufacturing. Starting from a parent BCP and using thiol-epoxy 'click' chemistry, we synthesize a library of BCPs that cover a large and complex parameter space. This allows us to readily identify feature-size-dependent BCP chemistries for 8-20-nm-pitch patterns. These blocks have similar surface energies for directed self-assembly, and control over the segregation strength to optimize the structure (favoured at higher segregation strengths) and defectivity (favoured at lower segregation strengths).
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Affiliation(s)
- Hongbo Feng
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, USA
| | - Moshe Dolejsi
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, USA
| | - Ning Zhu
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China
| | - Soonmin Yim
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, USA
| | - Whitney Loo
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, USA
| | - Peiyuan Ma
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, USA
| | - Chun Zhou
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, USA
| | - Gordon S W Craig
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, USA
| | - Wen Chen
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, USA
| | - Lei Wan
- Western Digital Corporation, San Jose, CA, USA
| | - Ricardo Ruiz
- The Molecular Foundry, Lawrence Berkeley National Lab, Berkeley, CA, USA
| | - Juan J de Pablo
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, USA
| | - Stuart J Rowan
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, USA.
- Department of Chemistry, University of Chicago, Chicago, IL, USA.
| | - Paul F Nealey
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, USA.
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4
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Cencer MM, Moore JS, Assary RS. Machine learning for polymeric materials: an introduction. POLYM INT 2021. [DOI: 10.1002/pi.6345] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Morgan M Cencer
- Department of Chemistry University of Illinois at Urbana‐Champaign Urbana IL USA
- Materials Science Division Argonne National Laboratory Lemont IL USA
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana‐Champaign Urbana IL USA
| | - Jeffrey S Moore
- Department of Chemistry University of Illinois at Urbana‐Champaign Urbana IL USA
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana‐Champaign Urbana IL USA
| | - Rajeev S Assary
- Materials Science Division Argonne National Laboratory Lemont IL USA
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5
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Affiliation(s)
- Brian A. Collins
- Physics and Astronomy Washington State University Pullman Washington USA
| | - Eliot Gann
- Material Measurement Laboratory National Institute of Standards and Technology Gaithersburg Maryland USA
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6
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Sunday DF, Thelen JL, Zhou C, Ren J, Nealey PF, Kline RJ. Buried Structure in Block Copolymer Films Revealed by Soft X-ray Reflectivity. ACS NANO 2021; 15:9577-9587. [PMID: 34014640 DOI: 10.1021/acsnano.0c09907] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Interactions between polymers and surfaces can be used to influence properties including mechanical performance in nanocomposites, the glass transition temperature, and the orientation of thin film block copolymers (BCPs). In this work we investigate how specific interactions between the substrate and BCPs with varying substrate affinity impact the interfacial width between polymer components. The interface width is generally assumed to be a function of the BCP properties and independent of the surface affinity or substrate proximity. Using resonant soft X-ray reflectivity the optical constants of the film can be controlled by changing the incident energy, thereby varying the depth sensitivity of the measurement. Resonant soft X-ray reflectivity measurements were conducted on films of polystyrene-b-poly(2-vinylpyridine) (PS-b-P2VP) and PS-b-poly(methyl methacrylate) (PS-b-PMMA), where the thickness of the film was varied from half the periodicity (L0) of the BCP to 5.5 L0. The results of this measurement on the PS-b-P2VP films show a significant expansion of the interface width immediately adjacent to the surface. This is likely caused by the strong adsorption of P2VP to the substrate, which constrains the mobility of the junction points, preventing them from reaching their equilibrium distribution and expanding the observed interface width. The interface width decays toward equilibrium moving away from the substrate, with the decay rate being a function of film thickness below a critical limit. The PMMA block appears to be more mobile, and the BCP interfaces near the substrate match their equilibrium value.
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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
| | - Jacob L Thelen
- Materials Science and Engineering Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States
| | - Chun Zhou
- Institute for Molecular Engineering, University of Chicago, 5801 S Ellis Ave, Chicago, Illinois 60637, United States
| | - Jiaxing Ren
- Institute for Molecular Engineering, University of Chicago, 5801 S Ellis Ave, Chicago, Illinois 60637, United States
| | - Paul F Nealey
- Institute for Molecular Engineering, University of Chicago, 5801 S Ellis Ave, Chicago, Illinois 60637, United States
| | - R Joseph Kline
- Materials Science and Engineering Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States
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7
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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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8
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Bezik CT, de Pablo JJ. Formation, Stability, and Annihilation of the Stitched Morphology in Block Copolymer Thin Films. Macromolecules 2020. [DOI: 10.1021/acs.macromol.0c01777] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Cody T. Bezik
- Institute for Molecular Engineering, University of Chicago, Chicago, lllinois 60637, United States
| | - Juan J. de Pablo
- Institute for Molecular Engineering, University of Chicago, Chicago, lllinois 60637, United States
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
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9
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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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10
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Sunday DF, Chen X, Albrecht TR, Nowak D, Delgadillo PR, Dazai T, Miyagi K, Maehashi T, Yamazaki A, Nealey PF, Kline RJ. The Influence of Additives on the Interfacial Width and Line Edge Roughness in Block Copolymer Lithography. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2020; 32:https://doi.org/10.1021/acs.chemmater.9b04833. [PMID: 33100517 PMCID: PMC7580231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The challenges of patterning next generation integrated circuits have driven the semiconductor industry to look outside of traditional lithographic methods in order to continue cost effective size scaling. The directed self-assembly (DSA) of block copolymers (BCPs) is a nanofabrication technique used to reduce the periodicity of patterns prepared with traditional optical methods. BCPs with large interaction parameters (χ eff), provide access to smaller pitches and reduced interface widths. Larger χ eff is also expected to be correlated with reduced line edge roughness (LER), a critical performance parameter in integrated circuits. One approach to increasing χ eff is blending the BCP with a phase selective additive, such as an Ionic liquid (IL). The IL does not impact the etching rates of either phase, and this enables a direct interrogation of whether the change in interface width driven by higher χ eff translates into lower LER. The effect of the IL on the layer thickness and interface width of a BCP are examined, along with the corresponding changes in LER in a DSA patterned sample. The results demonstrate that increased χ eff through additive blending will not necessarily translate to a lower LER, clarifying an important design criterion for future material systems.
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Affiliation(s)
- Daniel F. Sunday
- Materials Science and Engineering Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899
| | - Xuanxuan Chen
- Institute for Molecular Engineering, University of Chicago, 5801 S Ellis Ave, Chicago, IL 60637
| | | | | | | | - Takahiro Dazai
- Tokyo Ohka Kogyo, 1590 Tabata, Samukawa-Machi, Koza-Gun, Kanagawa 253-0114, Japan
| | - Ken Miyagi
- Tokyo Ohka Kogyo, 1590 Tabata, Samukawa-Machi, Koza-Gun, Kanagawa 253-0114, Japan
| | - Takaya Maehashi
- Tokyo Ohka Kogyo, 1590 Tabata, Samukawa-Machi, Koza-Gun, Kanagawa 253-0114, Japan
| | - Akiyoshi Yamazaki
- Tokyo Ohka Kogyo, 1590 Tabata, Samukawa-Machi, Koza-Gun, Kanagawa 253-0114, Japan
| | - Paul F. Nealey
- Institute for Molecular Engineering, University of Chicago, 5801 S Ellis Ave, Chicago, IL 60637
| | - R. Joseph Kline
- Materials Science and Engineering Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899
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11
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Chen X, Delgadillo PR, Jiang Z, Craig GSW, Gronheid R, Nealey PF. Defect Annihilation in the Directed Self-Assembly of Block Copolymers in Films with Increasing Thickness. Macromolecules 2019. [DOI: 10.1021/acs.macromol.9b01030] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Xuanxuan Chen
- Intel Corporation, 2501 NE Century Boulevard, Hillsboro, Oregon 97124, United States
- Institute for Molecular Engineering, University of Chicago, 5640 S Ellis Avenue, Chicago, Illinois 60637, United States
| | - Paulina R. Delgadillo
- Institute for Molecular Engineering, University of Chicago, 5640 S Ellis Avenue, Chicago, Illinois 60637, United States
- Imec, Kapeldreef 75, Leuven B-3001, Belgium
| | - Zhang Jiang
- X-ray Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States
| | - Gordon S. W. Craig
- Institute for Molecular Engineering, University of Chicago, 5640 S Ellis Avenue, Chicago, Illinois 60637, United States
| | | | - Paul F. Nealey
- Institute for Molecular Engineering, University of Chicago, 5640 S Ellis Avenue, Chicago, Illinois 60637, United States
- Material Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439, United States
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12
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Jackson NE, Webb MA, de Pablo JJ. Recent advances in machine learning towards multiscale soft materials design. Curr Opin Chem Eng 2019. [DOI: 10.1016/j.coche.2019.03.005] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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13
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14
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Abstract
Grazing-incidence small-angle X-ray scattering (GISAXS) is a powerful technique for measuring the nanostructure of coatings and thin films. However, GISAXS data are plagued by distortions that complicate data analysis. The detector image is a warped representation of reciprocal space because of refraction, and overlapping scattering patterns appear because of reflection. A method is presented to unwarp GISAXS data, recovering an estimate of the true undistorted scattering pattern. The method consists of first generating a guess for the structure of the reciprocal-space scattering by solving for a mutually consistent prediction from the transmission and reflection sub-components. This initial guess is then iteratively refined by fitting experimental GISAXS images at multiple incident angles, using the distorted-wave Born approximation (DWBA) to convert between reciprocal space and detector space. This method converges to a high-quality reconstruction for the undistorted scattering, as validated by comparing with grazing-transmission scattering data. This new method for unwarping GISAXS images will broaden the applicability of grazing-incidence techniques, allowing experimenters to inspect undistorted visualizations of their data and allowing a broader range of analysis methods to be applied to GI data.
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Affiliation(s)
- Jiliang Liu
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Kevin G. Yager
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY 11973, USA
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15
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Jiang X, Li J, Lee V, Jaeger HM, Heinonen OG, de Pablo JJ. Evolutionary strategy for inverse charge measurements of dielectric particles. J Chem Phys 2018; 148:234302. [DOI: 10.1063/1.5027435] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Xikai Jiang
- Institute for Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA
| | - Jiyuan Li
- Institute for Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA
| | - Victor Lee
- James Franck Institute and Department of Physics, University of Chicago, Chicago, Illinois 60637, USA
| | - Heinrich M. Jaeger
- James Franck Institute and Department of Physics, University of Chicago, Chicago, Illinois 60637, USA
| | - Olle G. Heinonen
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
- Northwestern-Argonne Institute for Science and Engineering, Evanston, Illinois 60208, USA
| | - Juan J. de Pablo
- Institute for Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
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16
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Hannon AF, Sunday DF, Bowen A, Khaira G, Ren J, Nealey PF, de Pablo JJ, Kline RJ. Optimizing self-consistent field theory block copolymer models with X-ray metrology. MOLECULAR SYSTEMS DESIGN & ENGINEERING 2018; 3:376-389. [PMID: 29892480 PMCID: PMC5992623 DOI: 10.1039/c7me00098g] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A block copolymer self-consistent field theory (SCFT) model is used for direct analysis of experimental X-ray scattering data obtained from thin films of polystyrene-b-poly(methyl methacrylate) (PS-b-PMMA) made from directed self-assembly. In a departure from traditional approaches, which reconstruct the real space structure using simple geometric shapes, we build on recent work that has relied on physics-based models to determine shape profiles and extract thermodynamic processing information from the scattering data. More specifically, an SCFT model, coupled to a covariance matrix adaptation evolutionary strategy (CMAES), is used to find the set of simulation parameters for the model that best reproduces the scattering data. The SCFT model is detailed enough to capture the essential physics of the copolymer self-assembly, but sufficiently simple to rapidly produce structure profiles needed for interpreting the scattering data. The ability of the model to produce a matching scattering profile is assessed, and several improvements are proposed in order to more accurately recreate the experimental observations. The predicted parameters are compared to those extracted from model fits via additional experimental methods and with predicted parameters from direct particle-based simulations of the same model, which incorporate the effects of fluctuations. The Flory-Huggins interaction parameter for PS-b-PMMA is found to be in agreement with reported ranges for this material. These results serve to strengthen the case for relying on physics-based models for direct analysis of scattering and light signal based experiments.
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Affiliation(s)
- Adam F Hannon
- Materials Science and Engineering Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899, USA
| | - Daniel F Sunday
- Materials Science and Engineering Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899, USA
| | - Alec Bowen
- Institute for Molecular Engineering, University of Chicago, 5801 S Ellis Ave, Chicago, IL 60637, USA
| | - Gurdaman Khaira
- Mentor Graphics Corporation, 8005 Boeckman Rd, Wilsonville, OR 97070, USA
| | - Jiaxing Ren
- Institute for Molecular Engineering, University of Chicago, 5801 S Ellis Ave, Chicago, IL 60637, USA
| | - Paul F Nealey
- Institute for Molecular Engineering, University of Chicago, 5801 S Ellis Ave, Chicago, IL 60637, USA
- Argonne National Laboratory, 9700 Cass Ave, Lemont, IL 60439, USA
| | - Juan J de Pablo
- Institute for Molecular Engineering, University of Chicago, 5801 S Ellis Ave, Chicago, IL 60637, USA
- Argonne National Laboratory, 9700 Cass Ave, Lemont, IL 60439, USA
| | - R Joseph Kline
- Materials Science and Engineering Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899, USA
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17
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Sunday DF, Maher MJ, Hannon AF, Liman CD, Tein S, Blachut G, Asano Y, Ellison CJ, Willson CG, Kline RJ. Characterizing the Interface Scaling of High χ Block Copolymers near the Order-Disorder Transition. Macromolecules 2017; 51:173-180. [PMID: 29706666 DOI: 10.1021/acs.macromol.7b01982] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Advancements in the directed self-assembly of block copolymers (BCPs) have prompted the development of new materials with larger effective interaction parameters (χe). This enables BCP systems with phase separation at increasingly small degrees of polymerization (N). Very often these systems reside near the order-disorder transition and fit between the weak and strong segregation limits where the behavior of BCP systems is not as thoroughly understood. Utilizing resonant soft X-ray reflectivity (RSoXR) enables both the BCP pitch (L0) and interface width (wM) to be determined simultaneously, through a direct characterization of the composition profile of BCP lamellae oriented parallel to a substrate. A series of high χe BCPs with χe ranging from ≈0.04 to 0.25 and χeN from 19 to 70 have been investigated. The L0/wm ratio serves as an important metric for the feasibility of a material for nanopatterning applications; the results of the RSoXR measurement are used to establish a relationship between χe and L0/wm. The results of this analysis are correlated with experimentally established limits for the functionality of BCPs in nanopatterning applications. These results also provide guidance for the magnitude of χe needed to achieve small interface width for samples with sub-10 nm L0.
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Affiliation(s)
- Daniel F Sunday
- Materials Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-1070, United States
| | - Michael J Maher
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Adam F Hannon
- Materials Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-1070, United States
| | - Christopher D Liman
- Materials Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-1070, United States
| | - Summer Tein
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, United States
| | - Gregory Blachut
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, United States
| | - Yusuke Asano
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Christopher J Ellison
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, United States.,Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - C Grant Willson
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States.,McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, United States
| | - R Joseph Kline
- Materials Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-1070, United States
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