1
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Pula P, Leniart A, Majewski PW. Solvent-assisted self-assembly of block copolymer thin films. SOFT MATTER 2022; 18:4042-4066. [PMID: 35608282 DOI: 10.1039/d2sm00439a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Solvent-assisted block copolymer self-assembly is a compelling method for processing and advancing practical applications of these materials due to the exceptional level of the control of BCP morphology and significant acceleration of ordering kinetics. Despite substantial experimental and theoretical efforts devoted to understanding of solvent-assisted BCP film ordering, the development of a universal BCP patterning protocol remains elusive; possibly due to a multitude of factors which dictate the self-assembly scenario. The aim of this review is to aggregate both seminal reports and the latest progress in solvent-assisted directed self-assembly and to provide the reader with theoretical background, including the outline of BCP ordering thermodynamics and kinetics phenomena. We also indicate significant BCP research areas and emerging high-tech applications where solvent-assisted processing might play a dominant role.
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Affiliation(s)
- Przemyslaw Pula
- Department of Chemistry, University of Warsaw, Warsaw 02089, Poland.
| | - Arkadiusz Leniart
- Department of Chemistry, University of Warsaw, Warsaw 02089, Poland.
| | - Pawel W Majewski
- Department of Chemistry, University of Warsaw, Warsaw 02089, Poland.
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2
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Park TW, Kang YL, Byun M, Hong SW, Ahn YS, Lee J, Park WI. Controlled self-assembly of block copolymers in printed sub-20 nm cross-bar structures. NANOSCALE ADVANCES 2021; 3:5083-5089. [PMID: 36132336 PMCID: PMC9418718 DOI: 10.1039/d1na00357g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Accepted: 07/25/2021] [Indexed: 06/15/2023]
Abstract
Directed self-assembly (DSA) of block copolymers (BCPs) has garnered much attention due to its excellent pattern resolution, simple process, and good compatibility with many other lithography methods for useful nanodevice applications. Here, we present a BCP-based multiple nanopatterning process to achieve three-dimensional (3D) pattern formation of metal/oxide hybrid nanostructures. We employed a self-assembled sub-20 nm SiO x line pattern as a master mold for nanotransfer printing (nTP) to generate a cross-bar array. By using the transfer-printed cross-bar structures as BCP-guiding templates, we can obtain well-ordered BCP microdomains in the distinct spaces of the nanotemplates through a confined BCP self-assembly process. We also demonstrate the morphological evolution of a cylinder-forming BCP by controlling the BCP film thickness, showing a clear morphological transition from cylinders to spheres in the designated nanospaces. Furthermore, we demonstrate how to control the number of BCP spheres within the cross-bar 3D pattern by adjusting the printing angle of the multiple nTP process to provide a suitable area for spontaneous BCP accommodation. This multiple-patterning-based approach is applicable to useful 3D nanofabrication of various devices with complex hybrid nanostructures.
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Affiliation(s)
- Tae Wan Park
- Electronic Convergence Materials Division, Korea Institute of Ceramic Engineering & Technology (KICET) 101 Soho-ro Jinju 52851 Republic of Korea
- Department of Materials Science and Engineering, Korea University Seoul 02841 Republic of Korea
| | - Young Lim Kang
- Department of Materials Science and Engineering, Pukyoung National University (PKNU) 45 Yongso-ro, Nam-gu Busan 48513 Republic of Korea
| | - Myunghwan Byun
- Department of Advanced Materials Engineering, Keimyung University 1095 Dalgubeol-daero Daegu 42601 Republic of Korea
| | - Suck Won Hong
- Department of Cogno-Mechatronics Engineering, Department of Optics and Mechatronics Engineering, College of Nanoscience and Nanotechnology, Pusan National University Busan 46241 Republic of Korea
| | - Yong-Sik Ahn
- Department of Materials Science and Engineering, Pukyoung National University (PKNU) 45 Yongso-ro, Nam-gu Busan 48513 Republic of Korea
| | - Junghoon Lee
- Department of Metallurgical Engineering, Pukyoung National University (PKNU) 45 Yongso-ro, Nam-gu Busan 48513 Republic of Korea
| | - Woon Ik Park
- Department of Materials Science and Engineering, Pukyoung National University (PKNU) 45 Yongso-ro, Nam-gu Busan 48513 Republic of Korea
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3
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Weller DW, Galuska L, Wang W, Ehlenburg D, Hong K, Gu X. Roll-to-Roll Scalable Production of Ordered Microdomains through Nonvolatile Additive Solvent Annealing of Block Copolymers. Macromolecules 2019. [DOI: 10.1021/acs.macromol.9b00772] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Daniel W. Weller
- School of Polymer Science and Engineering, The University of Southern Mississippi, Hattiesburg, Mississippi 39406, United States
| | - Luke Galuska
- School of Polymer Science and Engineering, The University of Southern Mississippi, Hattiesburg, Mississippi 39406, United States
| | - Weiyu Wang
- Chemical Sciences Divisions and Center for Nanophase Material Sciences (CNMS), Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Dakota Ehlenburg
- School of Polymer Science and Engineering, The University of Southern Mississippi, Hattiesburg, Mississippi 39406, United States
| | - Kunlun Hong
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Xiaodan Gu
- School of Polymer Science and Engineering, The University of Southern Mississippi, Hattiesburg, Mississippi 39406, United States
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4
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Zhang L, Liu L, Lin J. Well-ordered self-assembled nanostructures of block copolymer films via synergistic integration of chemoepitaxy and zone annealing. Phys Chem Chem Phys 2018; 20:498-508. [DOI: 10.1039/c7cp06261c] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The integrated chemical template/zone annealing method has the capability to rapidly fabricate well-aligned and well-oriented nanostructures over a macroscopic area.
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Affiliation(s)
- Liangshun Zhang
- Shanghai Key Laboratory of Advanced Polymeric Materials
- State Key Laboratory of Bioreactor Engineering
- Key Laboratory for Ultrafine Materials of Ministry of Education
- School of Materials Science and Engineering
- East China University of Science and Technology
| | - Lingling Liu
- Shanghai Key Laboratory of Advanced Polymeric Materials
- State Key Laboratory of Bioreactor Engineering
- Key Laboratory for Ultrafine Materials of Ministry of Education
- School of Materials Science and Engineering
- East China University of Science and Technology
| | - Jiaping Lin
- Shanghai Key Laboratory of Advanced Polymeric Materials
- State Key Laboratory of Bioreactor Engineering
- Key Laboratory for Ultrafine Materials of Ministry of Education
- School of Materials Science and Engineering
- East China University of Science and Technology
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5
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Chang CW, Cheng MH, Ko HW, Chu CW, Tu YH, Chen JT. Microwave-annealing-induced nanowetting of block copolymers in cylindrical nanopores. SOFT MATTER 2017; 14:35-41. [PMID: 29210440 DOI: 10.1039/c7sm02103h] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Block copolymers have attracted great attention because of their abilities to self-assemble into well-ordered microphase-separated structures. To generate nanopatterns of block copolymers with long-range ordering and low-defect densities in shorter time scales, microwave annealing has recently been applied. Microwave annealing, however, has so far only been used for block copolymer bulks and thin films. In this work, we discover that microwave annealing can be successfully applied to three-dimensional block copolymer nanostructures by studying the infiltration and microphase separation of block copolymers in cylindrical nanopores upon microwave irradiation. Cylinder-forming and lamella-forming poly(styrene-block-dimethylsiloxane) (PS-b-PDMS) are introduced into the nanopores of anodic aluminum oxide (AAO) templates. In addition, AAO templates with different pore sizes are used to study the effect of the commensurabilities between the pore diameters and the repeating periods of the block copolymers on the morphologies of the block copolymer nanostructures.
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Affiliation(s)
- Chun-Wei Chang
- Department of Applied Chemistry, National Chiao Tung University, Hsinchu 30010, Taiwan.
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6
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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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7
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Rokhlenko Y, Majewski PW, Larson SR, Gopalan P, Yager KG, Osuji CO. Implications of Grain Size Variation in Magnetic Field Alignment of Block Copolymer Blends. ACS Macro Lett 2017; 6:404-409. [PMID: 35610856 DOI: 10.1021/acsmacrolett.7b00036] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Recent experiments have highlighted the intrinsic magnetic anisotropy in coil-coil diblock copolymers, specifically in poly(styrene-block-4-vinylpyridine) (PS-b-P4VP), that enables magnetic field alignment at field strengths of a few tesla. We consider here the alignment response of two low molecular weight (MW) lamallae-forming PS-b-P4VP systems. Cooling across the disorder-order transition temperature (Todt) results in strong alignment for the higher MW sample (5.5K), whereas little alignment is discernible for the lower MW system (3.6K). This disparity under otherwise identical conditions of field strength and cooling rate suggests that different average grain sizes are produced during slow cooling of these materials, with larger grains formed in the higher MW material. Blending the block copolymers results in homogeneous samples which display Todt, d-spacings, and grain sizes that are intermediate between the two neat diblocks. Similarly, the alignment quality displays a smooth variation with the concentration of the higher MW diblock in the blends, and the size of grains likewise interpolates between limits set by the neat diblocks, with a factor of 3.5× difference in the grain size observed in high vs low MW neat diblocks. These results highlight the importance of grain growth kinetics in dictating the field response in block copolymers and suggests an unconventional route for the manipulation of such kinetics.
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Affiliation(s)
- Yekaterina Rokhlenko
- Department
of Chemical Engineering, Yale University, New Haven, Connecticut 06511, United States
| | - Paweł W. Majewski
- Center
for Functional Nanomaterials, Brookhaven National Lab, Upton, New York 11973, United States
- Department
of Chemistry, University of Warsaw, Warsaw 02093, Poland
| | - Steven R. Larson
- Department
of Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Padma Gopalan
- Department
of Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Kevin G. Yager
- Center
for Functional Nanomaterials, Brookhaven National Lab, Upton, New York 11973, United States
| | - Chinedum O. Osuji
- Department
of Chemical Engineering, Yale University, New Haven, Connecticut 06511, United States
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8
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Leonardi R. NC, Montgomery RD, Siqueira J, McAfee T, Drenski MF, Reed WF. Automatic Synthesis of Multimodal Polymers. MACROMOL REACT ENG 2017. [DOI: 10.1002/mren.201600072] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
| | | | - Julia Siqueira
- Tulane University New Orleans LA 70118 USA
- Universidade de São Paulo Lorena 12602‐810 Brazil
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9
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Wan X, Gao T, Zhang L, Lin J. Ordering kinetics of lamella-forming block copolymers under the guidance of various external fields studied by dynamic self-consistent field theory. Phys Chem Chem Phys 2017; 19:6707-6720. [DOI: 10.1039/c6cp08726d] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We theoretically engineer a new scheme, which integrates a permanent field for pattern registration and a dynamic external field for defect annihilation, to direct the self-assembly of block copolymers.
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Affiliation(s)
- Xiaomin Wan
- Shanghai Key Laboratory of Advanced Polymeric Materials
- State Key Laboratory of Bioreactor Engineering
- Key Laboratory for Ultrafine Materials of Ministry of Education
- School of Materials Science and Engineering
- East China University of Science and Technology
| | - Tong Gao
- Shanghai Key Laboratory of Advanced Polymeric Materials
- State Key Laboratory of Bioreactor Engineering
- Key Laboratory for Ultrafine Materials of Ministry of Education
- School of Materials Science and Engineering
- East China University of Science and Technology
| | - Liangshun Zhang
- Shanghai Key Laboratory of Advanced Polymeric Materials
- State Key Laboratory of Bioreactor Engineering
- Key Laboratory for Ultrafine Materials of Ministry of Education
- School of Materials Science and Engineering
- East China University of Science and Technology
| | - Jiaping Lin
- Shanghai Key Laboratory of Advanced Polymeric Materials
- State Key Laboratory of Bioreactor Engineering
- Key Laboratory for Ultrafine Materials of Ministry of Education
- School of Materials Science and Engineering
- East China University of Science and Technology
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10
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Zhao X, Yu X, Lee YI, Liu HG. Fabrication of Two-Dimensional Arrays of Diameter-Tunable PS-b-P2VP Nanowires at the Air/Water Interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:11819-11826. [PMID: 27783516 DOI: 10.1021/acs.langmuir.6b02396] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Composite thin films with well-defined and parallel nanowires were fabricated from the binary blends of a diblock copolymer polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP) and several homopolystyrenes (h-PSs) at the air/liquid interface through a facile technique, which involves solution self-assembly, interface adsorption, and further self-organization processes. It was confirmed that the nanowires that appeared at the air/water interface came from the cylindrical micelles formed in solution. Interestingly, the diameters of the nanowires are uniform and can be tuned precisely from 45 to 247 nm by incorporating the h-PS molecules into the micellar core. This parallel alignment of the nanowires has potential applications in optical devices and enables the nanowires to be used as templates to prepare functional nanostructures. The extent to which h-PS molecules with different molecular weights are able to influence the diameter control of the nanowires was also systematically investigated.
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Affiliation(s)
- Xingjuan Zhao
- Key Laboratory for Colloid and Interface Chemistry of Education Ministry, Shandong University , Jinan 250100, P. R. China
| | - Xiaoli Yu
- Key Laboratory for Colloid and Interface Chemistry of Education Ministry, Shandong University , Jinan 250100, P. R. China
| | - Yong-Ill Lee
- Anastro Laboratory, Department of Chemistry, Changwon National University , Changwon 641-773, Korea
| | - Hong-Guo Liu
- Key Laboratory for Colloid and Interface Chemistry of Education Ministry, Shandong University , Jinan 250100, P. R. China
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11
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Majewski PW, Yager KG. Rapid ordering of block copolymer thin films. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2016; 28:403002. [PMID: 27537062 DOI: 10.1088/0953-8984/28/40/403002] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Block-copolymers self-assemble into diverse morphologies, where nanoscale order can be finely tuned via block architecture and processing conditions. However, the ultimate usage of these materials in real-world applications may be hampered by the extremely long thermal annealing times-hours or days-required to achieve good order. Here, we provide an overview of the fundamentals of block-copolymer self-assembly kinetics, and review the techniques that have been demonstrated to influence, and enhance, these ordering kinetics. We discuss the inherent tradeoffs between oven annealing, solvent annealing, microwave annealing, zone annealing, and other directed self-assembly methods; including an assessment of spatial and temporal characteristics. We also review both real-space and reciprocal-space analysis techniques for quantifying order in these systems.
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Affiliation(s)
- Pawel W Majewski
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY, USA. Department of Chemistry, University of Warsaw, Warsaw, Poland
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12
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Cummins C, Ghoshal T, Holmes JD, Morris MA. Strategies for Inorganic Incorporation using Neat Block Copolymer Thin Films for Etch Mask Function and Nanotechnological Application. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2016; 28:5586-618. [PMID: 26749571 DOI: 10.1002/adma.201503432] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 10/07/2015] [Indexed: 05/12/2023]
Abstract
Block copolymers (BCPs) and their directed self-assembly (DSA) has emerged as a realizable complementary tool to aid optical patterning of device elements for future integrated circuit advancements. Methods to enhance BCP etch contrast for DSA application and further potential applications of inorganic nanomaterial features (e.g., semiconductor, dielectric, metal and metal oxide) are examined. Strategies to modify, infiltrate and controllably deposit inorganic materials by utilizing neat self-assembled BCP thin films open a rich design space to fabricate functional features in the nanoscale regime. An understanding and overview on innovative ways for the selective inclusion/infiltration or deposition of inorganic moieties in microphase separated BCP nanopatterns is provided. Early initial inclusion methods in the field and exciting contemporary reports to further augment etch contrast in BCPs for pattern transfer application are described. Specifically, the use of evaporation and sputtering methods, atomic layer deposition, sequential infiltration synthesis, metal-salt inclusion and aqueous metal reduction methodologies forming isolated nanofeatures are highlighted in di-BCP systems. Functionalities and newly reported uses for electronic and non-electronic technologies based on the inherent properties of incorporated inorganic nanostructures using di-BCP templates are highlighted. We outline the potential for extension of incorporation methods to triblock copolymer features for more diverse applications. Challenges and emerging areas of interest for inorganic infiltration of BCPs are also discussed.
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Affiliation(s)
- Cian Cummins
- Materials Research Group, Department of Chemistry and Tyndall National Institute, University College Cork, Cork, Ireland
- AMBER@CRANN, Trinity College Dublin, Dublin, Ireland
| | - Tandra Ghoshal
- Materials Research Group, Department of Chemistry and Tyndall National Institute, University College Cork, Cork, Ireland
- AMBER@CRANN, Trinity College Dublin, Dublin, Ireland
| | - Justin D Holmes
- AMBER@CRANN, Trinity College Dublin, Dublin, Ireland
- Materials Chemistry and Analysis Group, Department of Chemistry and Tyndall National Institute, University College Cork, Cork, Ireland
| | - Michael A Morris
- Materials Research Group, Department of Chemistry and Tyndall National Institute, University College Cork, Cork, Ireland
- AMBER@CRANN, Trinity College Dublin, Dublin, Ireland
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13
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Qiang Z, Ye C, Lin K, Becker ML, Cavicchi KA, Vogt BD. Evolution in surface morphology during rapid microwave annealing of
PS
‐
b
‐
PMMA
thin films. ACTA ACUST UNITED AC 2016. [DOI: 10.1002/polb.24043] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Zhe Qiang
- Department of Polymer Engineeringthe University of Akron250 S Forge StAkron Ohio44325
| | - Changhuai Ye
- Department of Polymer Engineeringthe University of Akron250 S Forge StAkron Ohio44325
| | - Kehua Lin
- Department of Polymer Engineeringthe University of Akron250 S Forge StAkron Ohio44325
| | - Matthew L. Becker
- Department of Polymer ScienceGoodyear Polymer Center, the University of Akron170 University CircleAkron Ohio44325
| | - Kevin A. Cavicchi
- Department of Polymer Engineeringthe University of Akron250 S Forge StAkron Ohio44325
| | - Bryan D. Vogt
- Department of Polymer Engineeringthe University of Akron250 S Forge StAkron Ohio44325
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14
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Cummins C, Mokarian-Tabari P, Andreazza P, Sinturel C, Morris MA. Solvothermal Vapor Annealing of Lamellar Poly(styrene)-block-poly(d,l-lactide) Block Copolymer Thin Films for Directed Self-Assembly Application. ACS APPLIED MATERIALS & INTERFACES 2016; 8:8295-8304. [PMID: 26950246 DOI: 10.1021/acsami.6b00765] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Solvothermal vapor annealing (STVA) was employed to induce microphase separation in a lamellar forming block copolymer (BCP) thin film containing a readily degradable block. Directed self-assembly of poly(styrene)-block-poly(d,l-lactide) (PS-b-PLA) BCP films using topographically patterned silicon nitride was demonstrated with alignment over macroscopic areas. Interestingly, we observed lamellar patterns aligned parallel as well as perpendicular (perpendicular microdomains to substrate in both cases) to the topography of the graphoepitaxial guiding patterns. PS-b-PLA BCP microphase separated with a high degree of order in an atmosphere of tetrahydrofuran (THF) at an elevated vapor pressure (at approximately 40-60 °C). Grazing incidence small-angle X-ray scattering (GISAXS) measurements of PS-b-PLA films reveal the through-film uniformity of perpendicular microdomains after STVA. Perpendicular lamellar orientation was observed on both hydrophilic and relatively hydrophobic surfaces with a domain spacing (L0) of ∼32.5 nm. The rapid removal of the PLA microdomains is demonstrated using a mild basic solution for the development of a well-defined PS mask template. GISAXS data reveal the through-film uniformity is retained following wet etching. The experimental results in this article demonstrate highly oriented PS-b-PLA microdomains after a short annealing period and facile PLA removal to form porous on-chip etch masks for nanolithography application.
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Affiliation(s)
- Cian Cummins
- Materials Research Group, Department of Chemistry and Tyndall National Institute, University College Cork , T12 YN60 Cork, Ireland
- AMBER, CRANN, Trinity College Dublin, Dublin 2, Ireland
| | - Parvaneh Mokarian-Tabari
- Materials Research Group, Department of Chemistry and Tyndall National Institute, University College Cork , T12 YN60 Cork, Ireland
- AMBER, CRANN, Trinity College Dublin, Dublin 2, Ireland
| | - Pascal Andreazza
- Interfaces, Confinement, Matériaux et Nanostructures, ICMN, UMR 7374, CNRS/Université d'Orléans, 1b Rue de la Férollerie, 45071 Orléans, France
| | - Christophe Sinturel
- Interfaces, Confinement, Matériaux et Nanostructures, ICMN, UMR 7374, CNRS/Université d'Orléans, 1b Rue de la Férollerie, 45071 Orléans, France
| | - Michael A Morris
- Materials Research Group, Department of Chemistry and Tyndall National Institute, University College Cork , T12 YN60 Cork, Ireland
- AMBER, CRANN, Trinity College Dublin, Dublin 2, Ireland
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15
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Murphy JN, Harris KD, Buriak JM. Automated Defect and Correlation Length Analysis of Block Copolymer Thin Film Nanopatterns. PLoS One 2015; 10:e0133088. [PMID: 26207990 PMCID: PMC4514826 DOI: 10.1371/journal.pone.0133088] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 06/22/2015] [Indexed: 11/22/2022] Open
Abstract
Line patterns produced by lamellae- and cylinder-forming block copolymer (BCP) thin films are of widespread interest for their potential to enable nanoscale patterning over large areas. In order for such patterning methods to effectively integrate with current technologies, the resulting patterns need to have low defect densities, and be produced in a short timescale. To understand whether a given polymer or annealing method might potentially meet such challenges, it is necessary to examine the evolution of defects. Unfortunately, few tools are readily available to researchers, particularly those engaged in the synthesis and design of new polymeric systems with the potential for patterning, to measure defects in such line patterns. To this end, we present an image analysis tool, which we have developed and made available, to measure the characteristics of such patterns in an automated fashion. Additionally we apply the tool to six cylinder-forming polystyrene-block-poly(2-vinylpyridine) polymers thermally annealed to explore the relationship between the size of each polymer and measured characteristics including line period, line-width, defect density, line-edge roughness (LER), line-width roughness (LWR), and correlation length. Finally, we explore the line-edge roughness, line-width roughness, defect density, and correlation length as a function of the image area sampled to determine each in a more rigorous fashion.
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Affiliation(s)
- Jeffrey N. Murphy
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada
- National Institute for Nanotechnology (NINT), Edmonton, Alberta, Canada
| | - Kenneth D. Harris
- National Institute for Nanotechnology (NINT), Edmonton, Alberta, Canada
| | - Jillian M. Buriak
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada
- National Institute for Nanotechnology (NINT), Edmonton, Alberta, Canada
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16
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Liu F, Luber EJ, Huck LA, Olsen BC, Buriak JM. Nanoscale plasmonic stamp lithography on silicon. ACS NANO 2015; 9:2184-93. [PMID: 25654172 DOI: 10.1021/acsnano.5b00312] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Nanoscale lithography on silicon is of interest for applications ranging from computer chip design to tissue interfacing. Block copolymer-based self-assembly, also called directed self-assembly (DSA) within the semiconductor industry, can produce a variety of complex nanopatterns on silicon, but these polymeric films typically require transformation into functional materials. Here we demonstrate how gold nanopatterns, produced via block copolymer self-assembly, can be incorporated into an optically transparent flexible PDMS stamp, termed a plasmonic stamp, and used to directly functionalize silicon surfaces on a sub-100 nm scale. We propose that the high intensity electric fields that result from the localized surface plasmons of the gold nanoparticles in the plasmonic stamps upon illumination with low intensity green light, lead to generation of electron-hole pairs in the silicon that drive spatially localized hydrosilylation. This approach demonstrates how localized surface plasmons can be used to enable functionalization of technologically relevant surfaces with nanoscale control.
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Affiliation(s)
- Fenglin Liu
- Department of Chemistry, University of Alberta , 11227 Saskatchewan Drive, Edmonton, AB T6G 2G2, Canada
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Mokarian-Tabari P, Cummins C, Rasappa S, Simao C, Sotomayor Torres CM, Holmes JD, Morris MA. Study of the kinetics and mechanism of rapid self-assembly in block copolymer thin films during solvo-microwave annealing. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:10728-10739. [PMID: 25137566 DOI: 10.1021/la503137q] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Microwave annealing is an emerging technique for achieving ordered patterns of block copolymer films on substrates. Little is understood about the mechanisms of microphase separation during the microwave annealing process and how it promotes the microphase separation of the blocks. Here, we use controlled power microwave irradiation in the presence of tetrahydrofuran (THF) solvent, to achieve lateral microphase separation in high-χ lamellar-forming poly(styrene-b-lactic acid) PS-b-PLA. A highly ordered line pattern was formed within seconds on silicon, germanium and silicon on insulator (SOI) substrates. In-situ temperature measurement of the silicon substrate coupled to condition changes during "solvo-microwave" annealing allowed understanding of the processes to be attained. Our results suggest that the substrate has little effect on the ordering process and is essentially microwave transparent but rather, it is direct heating of the polar THF molecules that causes microphase separation. It is postulated that the rapid interaction of THF with microwaves and the resultant temperature increase to 55 °C within seconds causes an increase of the vapor pressure of the solvent from 19.8 to 70 kPa. This enriched vapor environment increases the plasticity of both PS and PLA chains and leads to the fast self-assembly kinetics. Comparing the patterns formed on silicon, germanium and silicon on insulator (SOI) and also an in situ temperature measurement of silicon in the oven confirms the significance of the solvent over the role of substrate heating during "solvo-microwave" annealing. Besides the short annealing time which has technological importance, the coherence length is on a micron scale and dewetting is not observed after annealing. The etched pattern (PLA was removed by an Ar/O2 reactive ion etch) was transferred to the underlying silicon substrate fabricating sub-20 nm silicon nanowires over large areas demonstrating that the morphology is consistent both across and through the film.
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18
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Monte Carlo simulation on layered polymeric films. CHINESE JOURNAL OF POLYMER SCIENCE 2014. [DOI: 10.1007/s10118-014-1446-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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19
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Jin C, Murphy JN, Harris KD, Buriak JM. Deconvoluting the mechanism of microwave annealing of block copolymer thin films. ACS NANO 2014; 8:3979-3991. [PMID: 24655292 DOI: 10.1021/nn5009098] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The self-assembly of block copolymer (BCP) thin films is a versatile method for producing periodic nanoscale patterns with a variety of shapes. The key to attaining a desired pattern or structure is the annealing step undertaken to facilitate the reorganization of nanoscale phase-segregated domains of the BCP on a surface. Annealing BCPs on silicon substrates using a microwave oven has been shown to be very fast (seconds to minutes), both with and without contributions from solvent vapor. The mechanism of the microwave annealing process remains, however, unclear. This work endeavors to uncover the key steps that take place during microwave annealing, which enable the self-assembly process to proceed. Through the use of in situ temperature monitoring with a fiber optic temperature probe in direct contact with the sample, we have demonstrated that the silicon substrate on which the BCP film is cast is the dominant source of heating if the doping of the silicon wafer is sufficiently low. Surface temperatures as high as 240 °C are reached in under 1 min for lightly doped, high resistivity silicon wafers (n- or p-type). The influence of doping, sample size, and BCP composition was analyzed to rule out other possible mechanisms. In situ temperature monitoring of various polymer samples (PS, P2VP, PMMA, and the BCPs used here) showed that the polymers do not heat to any significant extent on their own with microwave irradiation of this frequency (2.45 GHz) and power (∼600 W). It was demonstrated that BCP annealing can be effectively carried out in 60 s on non-microwave-responsive substrates, such as highly doped silicon, indium tin oxide (ITO)-coated glass, glass, and Kapton, by placing a piece of high resistivity silicon wafer in contact with the sample-in this configuration, the silicon wafer is termed the heating element. Annealing and self-assembly of polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP) and polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) BCPs into horizontal cylinder structures were shown to take place in under 1 min, using a silicon wafer heating element, in a household microwave oven. Defect densities were calculated and were shown to decrease with higher maximum obtained temperatures. Conflicting results in the literature regarding BCP annealing with microwave are explained in light of the results obtained in this study.
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Affiliation(s)
- Cong Jin
- National Institute for Nanotechnology , 11421 Saskatchewan Drive, Edmonton, Alberta T6G 2M9, Canada
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20
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Gu X, Gunkel I, Russell TP. Pattern transfer using block copolymers. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2013; 371:20120306. [PMID: 24000358 DOI: 10.1098/rsta.2012.0306] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
To meet the increasing demand for patterning smaller feature sizes, a lithography technique is required with the ability to pattern sub-20 nm features. While top-down photolithography is approaching its limit in the continued drive to meet Moore's law, the use of directed self-assembly (DSA) of block copolymers (BCPs) offers a promising route to meet this challenge in achieving nanometre feature sizes. Recent developments in BCP lithography and in the DSA of BCPs are reviewed. While tremendous advances have been made in this field, there are still hurdles that need to be overcome to realize the full potential of BCPs and their actual use.
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Affiliation(s)
- Xiaodan Gu
- Polymer Science and Engineering Department, University of Massachusetts at Amherst, 120 Governors Drive, Amherst, MA 01003, USA
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21
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Borah D, Senthamaraikannan R, Rasappa S, Kosmala B, Holmes JD, Morris MA. Swift nanopattern formation of PS-b-PMMA and PS-b-PDMS block copolymer films using a microwave assisted technique. ACS NANO 2013; 7:6583-6596. [PMID: 23859379 DOI: 10.1021/nn4035519] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Microphase separation of block copolymer (BCPs) thin films has high potential as a surface patterning technique. However, the process times (during thermal or solvent anneal) can be inordinately long, and for it to be introduced into manufacturing, there is a need to reduce these times from hours to minutes. We report here BCP self-assembly on two different systems, polystyrene-b-polymethylmethacrylate (PS-b-PMMA) (lamellar- and cylinder-forming) and polystyrene-b-polydimethylsiloxane (PS-b-PDMS) (cylinder-forming) by microwave irradiation to achieve ordering in short times. Unlike previous reports of microwave assisted microphase segregation, the microwave annealing method reported here was undertaken without addition of solvents. Factors such as the anneal time and temperature, BCP film thickness, substrate surface type, etc. were investigated for their effect of the ordering behavior. The microwave technique was found to be compatible with graphoepitaxy, and in the case of the PS-b-PDMS system, long-range translational alignment of the BCP domains was observed within the topographic patterns. To demonstrate the usefulness of the method, the BCP nanopatterns were turned into an 'on-chip' resist by an initial plasma etch and these were used to transfer the pattern into the substrate.
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Affiliation(s)
- Dipu Borah
- Materials Chemistry Section, Department of Chemistry, University College Cork, College Road, Cork, Ireland
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22
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Wu NLY, Harris KD, Buriak JM. Conversion of bilayers of PS-b-PDMS block copolymer into closely packed, aligned silica nanopatterns. ACS NANO 2013; 7:5595-5606. [PMID: 23675942 DOI: 10.1021/nn401968t] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Block copolymer (BCP) self-assembly is an effective and versatile approach for the production of complex nanopatterned interfaces. Monolayers of BCP films can be harnessed to produce a variety of different patterns, including lines, with specific spacings and order. In this work, bilayers of cylinder-forming polystyrene-block-polydimethylsiloxane block copolymer (PS-b-PDMS) were transformed into arrays of silica lines with half the pitch normally attained for conventional monolayers, with the PDMS acting as the source for the SiOx. The primary hurdle was ensuring the bilayer silica lines were distinctly separate; to attain the control necessary to prevent overlap, a number of variables related to the materials and self-assembly process were investigated in detail. Developing a detailed understanding of BCP film swelling during solvent annealing, blending of the PS-b-PDMS with PS homopolymer, utilization of a surface brush layer, and adjustment of the plasma exposure conditions, distinct and separate silica lines were prepared. On the microscale, the sample coverage of PS-b-PDMS bilayers was investigated and maximized to attain >95% bilayers under defined conditions. The bilayer BCP structures were also amenable to graphoepitaxy, and thus, dense and highly ordered arrays of silica line patterns with tightly controlled width and pitch were fabricated and distributed uniformly across a Si surface.
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Affiliation(s)
- Nathanael L Y Wu
- National Institute for Nanotechnology (NINT), National Research Council, 11421 Saskatchewan Drive, Edmonton, Alberta T6G 2M9, Canada
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23
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Borah D, Shaw MT, Holmes JD, Morris MA. Sub-10 nm feature size PS-b-PDMS block copolymer structures fabricated by a microwave-assisted solvothermal process. ACS APPLIED MATERIALS & INTERFACES 2013; 5:2004-2012. [PMID: 23421383 DOI: 10.1021/am302830w] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Block copolymer (BCP) microphase separation at surfaces might enable the generation of substrate features in a scalable, manufacturable, bottom-up fashion provided that pattern structure, orientation, alignment can be strictly controlled. A further requirement is that self-assembly takes place within periods of the order of minutes so that continuous manufacturingprocesses do not require lengthy pretreatments and sample storageleading to contamination and large facility costs. We report here microwave-assisted solvothermal (in toluene environments) self-assembly and directed self-assembly of a very low molecular weight cylinder-forming polystyrene-block-polydimethylsiloxane (PS-b-PDMS) BCP on planar and patterned silicon nitride (Si3N4) substrates. Good pattern ordering was achieved in the order of minutes. Factors affecting BCP self-assembly, notably anneal time and temperature were studied and seen to have significant effects. Graphoepitaxy to direct self-assembly in the BCP yielded promising results producing BCP patterns with long-range translational alignment commensurate with the pitch period of the topographic patterns. This rapid BCP ordering method is consistent with the standard thermal/solvent anneal processes.
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Affiliation(s)
- Dipu Borah
- Materials Chemistry Section, Department of Chemistry, University College Cork, College Road, Cork, Ireland
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24
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Takahashi H, Laachi N, Delaney KT, Hur SM, Weinheimer CJ, Shykind D, Fredrickson GH. Defectivity in Laterally Confined Lamella-Forming Diblock Copolymers: Thermodynamic and Kinetic Aspects. Macromolecules 2012. [DOI: 10.1021/ma300993x] [Citation(s) in RCA: 121] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Hassei Takahashi
- Materials
Research Laboratory, University of California, Santa Barbara, California
93106, United States
- Department
of Chemical Engineering, University of California, Santa Barbara, California
93106, United States
| | - Nabil Laachi
- Materials
Research Laboratory, University of California, Santa Barbara, California
93106, United States
| | - Kris T. Delaney
- Materials
Research Laboratory, University of California, Santa Barbara, California
93106, United States
| | - Su-Mi Hur
- Materials
Research Laboratory, University of California, Santa Barbara, California
93106, United States
- Department
of Chemical Engineering, University of California, Santa Barbara, California
93106, United States
| | | | - David Shykind
- Intel Corporation, Hillsboro, Oregon 97124, United
States
| | - Glenn H. Fredrickson
- Materials
Research Laboratory, University of California, Santa Barbara, California
93106, United States
- Department
of Chemical Engineering, University of California, Santa Barbara, California
93106, United States
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25
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Mishra V, Fredrickson GH, Kramer EJ. Effect of film thickness and domain spacing on defect densities in directed self-assembly of cylindrical morphology block copolymers. ACS NANO 2012; 6:2629-2641. [PMID: 22339501 DOI: 10.1021/nn205120j] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Directed assembly of block copolymer thin films is recognized as a high-throughput, low-cost complement to optical lithography with the ability to overcome the 32 nm natural resolution limit of conventional lithographic techniques. For bulk block copolymer systems, desired feature sizes ranging from 5 to 100 nm can be obtained by controlling the molecular weight and composition of a block copolymer, as long as the bulk order-disorder temperature (ODT) is such that the copolymer is well-segregated at the processing conditions. However, our studies on graphoepitaxially aligned cylindrical morphology block copolymer monolayer and bilayer films demonstrate that, as domain sizes are reduced, the block copolymer becomes increasingly susceptible to an unacceptably high density of thermally generated defects, resulting in a significant reduction of the ODT. Thus, in thin films, the minimum feature spacing accessible is limited by thermal defect generation and not by the bulk ODT. Our experimental studies on monolayer films of cylindrical morphology polystyrene-b-poly(2-vinyl pyridine) with microdomain spacings approaching 20 nm reveal that defect densities and the ODT are surprisingly sensitive to variations as small as 2 nm in the microdomain spacing. Additionally, the monolayer and bilayer ODT differ by nearly 100 °C when the monolayer domain spacing is 20 nm, while the difference is only 20 °C when the monolayer domain spacing is 22 nm. We explain this behavior using a quantitative estimation of the energetic cost of defect production in terms of the domain spacing, χN, and block copolymer composition. These studies reveal unexpected consequences on the equilibrium defect densities of thin film block copolymers which must be accounted for when designing a block-copolymer-based directed-assembly process.
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Affiliation(s)
- Vindhya Mishra
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, USA
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