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Park SY, Lee S, Yang J, Kang MS. Patterning Quantum Dots via Photolithography: A Review. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2300546. [PMID: 36892995 DOI: 10.1002/adma.202300546] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 02/28/2023] [Indexed: 06/18/2023]
Abstract
Pixelating patterns of red, green, and blue quantum dots (QDs) is a critical challenge for realizing high-end displays with bright and vivid images for virtual, augmented, and mixed reality. Since QDs must be processed from a solution, their patterning process is completely different from the conventional techniques used in the organic light-emitting diode and liquid crystal display industries. Although innovative QD patterning technologies are being developed, photopatterning based on the light-induced chemical conversion of QD films is considered one of the most promising methods for forming micrometer-scale QD patterns that satisfy the precision and fidelity required for commercialization. Moreover, the practical impact will be significant as it directly exploits mature photolithography technologies and facilities that are widely available in the semiconductor industry. This article reviews recent progress in the effort to form QD patterns via photolithography. The review begins with a general description of the photolithography process. Subsequently, different types of photolithographical methods applicable to QD patterning are introduced, followed by recent achievements using these methods in forming high-resolution QD patterns. The paper also discusses prospects for future research directions.
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Affiliation(s)
- Se Young Park
- Department of Chemical and Biomolecular Engineering, Sogang University, Seoul, 04107, South Korea
| | - Seongjae Lee
- School of Chemical and Biological Engineering, Seoul National University, Seoul, 08826, South Korea
| | - Jeehye Yang
- Department of Chemical and Biomolecular Engineering, Sogang University, Seoul, 04107, South Korea
| | - Moon Sung Kang
- Department of Chemical and Biomolecular Engineering, Sogang University, Seoul, 04107, South Korea
- Institute of Emergent Materials, Sogang University, Seoul, 04107, South Korea
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2
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Wojtecki R, Ma J, Cordova I, Arellano N, Lionti K, Magbitang T, Pattison TG, Zhao X, Delenia E, Lanzillo N, Hess AE, Nathel NF, Bui H, Rettner C, Wallraff G, Naulleau P. Additive Lithography-Organic Monolayer Patterning Coupled with an Area-Selective Deposition. ACS APPLIED MATERIALS & INTERFACES 2021; 13:9081-9090. [PMID: 33471496 DOI: 10.1021/acsami.0c16817] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The combination of area-selective deposition (ASD) with a patternable organic monolayer provides a versatile additive lithography platform, enabling the generation of a variety of nanoscale feature geometries. Stearate hydroxamic acid self-assembled monolayers (SAMs) were patterned with extreme ultraviolet (λ = 13.5 nm) or electron beam irradiation and developed with ASD to achieve line space patterns as small as 50 nm. Density functional theory was employed to aid in the synthesis of hydroxamic acid derivatives with optimized packing density to enhance the imaging contrast and improve dose sensitivity. Near-edge X-ray absorption fine structure spectroscopy and infrared spectroscopy reveal that the imaging mechanism is based on improved deposition inhibition provided by the cross-linking of the SAM to produce a more effective barrier during a subsequent deposition step. With patterned substrates composed of coplanar copper lines and silicon spacers, hydroxamic acids selectively formed monolayers on the metal portions and could undergo a pattern-wise exposure followed by ASD in the first combination of a patternable monolayer with ASD. This material system presents an additional capability compared to traditional ASD approaches that generally reflect a starting patterned surface. Furthermore, this bottoms-up additive approach to lithography may be a viable alternative to subtractive nanoscale feature generation.
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Affiliation(s)
- Rudy Wojtecki
- International Business Machines-Almaden Research Center, 650 Harry Road, San Jose, California 95110, United States
| | - Jonathan Ma
- Center for X-ray Optics, Materials Science Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd., Berkeley, California 94720, United States
| | - Isvar Cordova
- Center for X-ray Optics, Materials Science Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd., Berkeley, California 94720, United States
| | - Noel Arellano
- International Business Machines-Almaden Research Center, 650 Harry Road, San Jose, California 95110, United States
| | - Krystelle Lionti
- International Business Machines-Almaden Research Center, 650 Harry Road, San Jose, California 95110, United States
| | - Teddie Magbitang
- International Business Machines-Almaden Research Center, 650 Harry Road, San Jose, California 95110, United States
| | - Thomas G Pattison
- Polymer Science Group, Department of Chemical Engineering, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Xiao Zhao
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Department of Materials Science and Engineering, University of California at Berkeley, Berkeley, California 94720, United States
| | - Eugene Delenia
- International Business Machines-Almaden Research Center, 650 Harry Road, San Jose, California 95110, United States
| | - Nicholas Lanzillo
- International Business Machines-Semiconductor Technology Research, 257 Fuller Road, Albany, New York 12203, United States
| | - Alexander E Hess
- International Business Machines-Almaden Research Center, 650 Harry Road, San Jose, California 95110, United States
| | - Noah Fine Nathel
- International Business Machines-Almaden Research Center, 650 Harry Road, San Jose, California 95110, United States
| | - Holt Bui
- International Business Machines-Almaden Research Center, 650 Harry Road, San Jose, California 95110, United States
| | - Charles Rettner
- International Business Machines-Almaden Research Center, 650 Harry Road, San Jose, California 95110, United States
| | - Gregory Wallraff
- International Business Machines-Almaden Research Center, 650 Harry Road, San Jose, California 95110, United States
| | - Patrick Naulleau
- Center for X-ray Optics, Materials Science Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd., Berkeley, California 94720, United States
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Electron Beam Induced Tailoring of Electrical Characteristics of Organic Semiconductor Films. CHEMISTRY AFRICA-A JOURNAL OF THE TUNISIAN CHEMICAL SOCIETY 2020. [DOI: 10.1007/s42250-020-00168-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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4
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Dement DB, Quan MK, Ferry VE. Nanoscale Patterning of Colloidal Nanocrystal Films for Nanophotonic Applications Using Direct Write Electron Beam Lithography. ACS APPLIED MATERIALS & INTERFACES 2019; 11:14970-14979. [PMID: 30932468 DOI: 10.1021/acsami.9b01159] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The small size of colloidal nanocrystal quantum dots (QDs) leads to a variety of unique optical properties that are well-suited to nanophotonics, including bright, tunable photoluminescence (PL). However, exploring the properties of solid QD assemblies at the nanoscale has proven challenging because of the limitations in the nanoscale QD patterning methods. Generally, the precise placement of QD solids is difficult to achieve, especially for tall structures with multiple QD layers, and when it is achieved the patterns often cannot withstand the further processing steps required for final device construction. Direct electron beam lithography of QDs has emerged as a straightforward patterning process that does not require ligand exchange and results in structures that retain bright PL. Here, we demonstrate that direct patterning QD films on substrates treated with a self-assembled monolayer of octadecyltrichlorosilane allows us to create feature sizes as thin as 30 nm with heights of multiple layers and characterize the pattern resolution, robustness, and placement accuracy. These structures withstand sonication in a variety of solvents, and the structures are placed within 20 nm of their intended location nearly 100% of the time. We further show how this patterning method can be applied to nanophotonics by measuring the complex refractive index of the QD materials to model the absorption and scattering cross sections of QD structures of various sizes and shapes. These simulations reveal that edge effects arising from the finite shape of the QD nanostructure lead to substantial absorption enhancement when compared to an equivalent volume region taken from a continuous QD film. Finally, we explore more complex structures by patterning QD arrays, multilayer QD structures, and QD disks inside plasmonic resonators.
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Affiliation(s)
- Dana B Dement
- Department of Chemical Engineering and Materials Science , University of Minnesota , 421 Washington Avenue SE , Minneapolis , Minnesota 55455 , United States
| | - Matthew K Quan
- Department of Chemical Engineering and Materials Science , University of Minnesota , 421 Washington Avenue SE , Minneapolis , Minnesota 55455 , United States
| | - Vivian E Ferry
- Department of Chemical Engineering and Materials Science , University of Minnesota , 421 Washington Avenue SE , Minneapolis , Minnesota 55455 , United States
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5
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Szczerbiński J, Gyr L, Kaeslin J, Zenobi R. Plasmon-Driven Photocatalysis Leads to Products Known from E-beam and X-ray-Induced Surface Chemistry. NANO LETTERS 2018; 18:6740-6749. [PMID: 30277787 DOI: 10.1021/acs.nanolett.8b02426] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Plasmonic metal nanostructures can concentrate incident optical fields in nanometer-sized volumes, called hot spots. This leads to enhanced optical responses of molecules in such a hot spot but also to chemical transformations, driven by plasmon-induced hot carriers. Here, we employ tip-enhanced Raman spectroscopy (TERS) to study the mechanism of these reactions in situ at the level of a single hot spot. Direct spectroscopic measurements reveal the energy distribution of hot electrons, as well as the temperature changes due to plasmonic heating. Therefore, charge-driven reactions can be distinguished from thermal reaction pathways. The products of the hot-carrier-driven reactions are strikingly similar to the ones known from X-ray or e-beam-induced surface chemistry despite the >100-fold energy difference between visible and X-ray photons. Understanding the analogies between those two scenarios implies new strategies for rational design of plasmonic photocatalytic reactions and for the elimination of photoinduced damage in plasmon-enhanced spectroscopy.
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Affiliation(s)
- Jacek Szczerbiński
- Department of Chemistry and Applied Biosciences, Laboratory of Organic Chemistry , ETH Zurich , 8093 Zurich , Switzerland
| | - Luzia Gyr
- Department of Chemistry and Applied Biosciences, Laboratory of Organic Chemistry , ETH Zurich , 8093 Zurich , Switzerland
| | - Jérôme Kaeslin
- Department of Chemistry and Applied Biosciences, Laboratory of Organic Chemistry , ETH Zurich , 8093 Zurich , Switzerland
| | - Renato Zenobi
- Department of Chemistry and Applied Biosciences, Laboratory of Organic Chemistry , ETH Zurich , 8093 Zurich , Switzerland
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6
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Martens I, Fisher EA, Bizzotto D. Direct Mapping of Heterogeneous Surface Coverage in DNA-Functionalized Gold Surfaces with Correlated Electron and Fluorescence Microscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:2425-2431. [PMID: 29361826 DOI: 10.1021/acs.langmuir.7b03766] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The characterization of biofunctionalized surfaces such as alkanethiol self-assembled monolayers (SAMs) on gold modified with DNA or other biomolecules is a challenging analytical problem, and access to a routine method is desirable. Despite substantial investigation from structural and mechanistic perspectives, robust and high-throughput metrology tools for SAMs remain elusive but essential for the continued development of these devices. We demonstrate that scanning electron microscopy (SEM) can provide image contrast of the molecular interface during SAM functionalization. The high-speed, large magnification range, and ease of use make this widely available technique a powerful platform for measuring the structure and composition of SAM surfaces. This increased throughput allows for a better understanding of the nonideal spatial heterogeneity characteristic of SAMs utilized in real-world conditions. SEM image contrast is characterized through the use of fluorescently labeled DNA, which enables correlative SEM and fluorescence microscopy. This allows identification of the DNA-modified regions at resolutions that approach the size of the biomolecule. The effect of electron beam irradiation dose is explored, which leads to straightforward lithographic patterning of DNA SAMs with nanometer resolution and with control over the surface coverage of specifically adsorbed DNA.
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Affiliation(s)
- Isaac Martens
- Advanced Materials and Proceess Engineering Laboratory (AMPEL) and ‡Department of Chemistry, University of British Columbia , Vancouver V6T 1Z1, Canada
| | - Elizabeth A Fisher
- Advanced Materials and Proceess Engineering Laboratory (AMPEL) and ‡Department of Chemistry, University of British Columbia , Vancouver V6T 1Z1, Canada
| | - Dan Bizzotto
- Advanced Materials and Proceess Engineering Laboratory (AMPEL) and ‡Department of Chemistry, University of British Columbia , Vancouver V6T 1Z1, Canada
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7
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Palazon F, Prato M, Manna L. Writing on Nanocrystals: Patterning Colloidal Inorganic Nanocrystal Films through Irradiation-Induced Chemical Transformations of Surface Ligands. J Am Chem Soc 2017; 139:13250-13259. [PMID: 28772078 PMCID: PMC6284209 DOI: 10.1021/jacs.7b05888] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Indexed: 11/29/2022]
Abstract
In the past couple of decades, colloidal inorganic nanocrystals (NCs) and, more specifically, semiconductor quantum dots (QDs) have emerged as crucial materials for the development of nanoscience and nanotechnology, with applications in very diverse areas such as optoelectronics and biotechnology. Films made of inorganic NCs deposited on a substrate can be patterned by e-beam lithography, altering the structure of their capping ligands and thus allowing exposed areas to remain on the substrate while non-exposed areas are redispersed in a solvent, as in a standard lift-off process. This methodology can be described as a "direct" lithography process, since the exposure is performed directly on the material of interest, in contrast with conventional lithography which uses a polymeric resist as a mask for subsequent material deposition (or etching). A few reports from the late 1990s and early 2000s used such direct lithography to fabricate electrical wires from metallic NCs. However, the poor conductivity obtained through this process hindered the widespread use of the technique. In the early 2010s, the same method was used to define fluorescent patterns on QD films, allowing for further applications in biosensing. For the past 2-3 years, direct lithography on NC films with e-beams and X-rays has gone through an important development as it has been demonstrated that it can tune further transformations on the NCs, leading to more complex patternings and opening a whole new set of possible applications. This Perspective summarizes the findings of the past 20 years on direct lithography on NC films with a focus on the latest developments on QDs from 2014 and provides different potential future outcomes of this promising technique.
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Affiliation(s)
- Francisco Palazon
- Nanochemistry
Department and Materials Characterization Facility, Istituto
Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
| | - Mirko Prato
- Nanochemistry
Department and Materials Characterization Facility, Istituto
Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
| | - Liberato Manna
- Nanochemistry
Department and Materials Characterization Facility, Istituto
Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
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8
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Rückriem K, Grotheer S, Vieker H, Penner P, Beyer A, Gölzhäuser A, Swiderek P. Efficient electron-induced removal of oxalate ions and formation of copper nanoparticles from copper(II) oxalate precursor layers. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2016; 7:852-861. [PMID: 27547602 PMCID: PMC4979688 DOI: 10.3762/bjnano.7.77] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 05/25/2016] [Indexed: 06/06/2023]
Abstract
Copper(II) oxalate grown on carboxy-terminated self-assembled monolayers (SAM) using a step-by-step approach was used as precursor for the electron-induced synthesis of surface-supported copper nanoparticles. The precursor material was deposited by dipping the surfaces alternately in ethanolic solutions of copper(II) acetate and oxalic acid with intermediate thorough rinsing steps. The deposition of copper(II) oxalate and the efficient electron-induced removal of the oxalate ions was monitored by reflection absorption infrared spectroscopy (RAIRS). Helium ion microscopy (HIM) reveals the formation of spherical nanoparticles with well-defined size and X-ray photoelectron spectroscopy (XPS) confirms their metallic nature. Continued irradiation after depletion of oxalate does not lead to further particle growth giving evidence that nanoparticle formation is primarily controlled by the available amount of precursor.
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Affiliation(s)
- Kai Rückriem
- University of Bremen, Institute for Applied and Physical Chemistry, Fachbereich 2 (Chemie/Biologie), Leobener Straße / NW 2, Postfach 330440, D-28334 Bremen, Germany
| | - Sarah Grotheer
- University of Bremen, Institute for Applied and Physical Chemistry, Fachbereich 2 (Chemie/Biologie), Leobener Straße / NW 2, Postfach 330440, D-28334 Bremen, Germany
| | - Henning Vieker
- Physics of Supramolecular Systems, Bielefeld University, D-33615 Bielefeld, Germany
| | - Paul Penner
- Physics of Supramolecular Systems, Bielefeld University, D-33615 Bielefeld, Germany
| | - André Beyer
- Physics of Supramolecular Systems, Bielefeld University, D-33615 Bielefeld, Germany
| | - Armin Gölzhäuser
- Physics of Supramolecular Systems, Bielefeld University, D-33615 Bielefeld, Germany
| | - Petra Swiderek
- University of Bremen, Institute for Applied and Physical Chemistry, Fachbereich 2 (Chemie/Biologie), Leobener Straße / NW 2, Postfach 330440, D-28334 Bremen, Germany
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9
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Nawroth JF, Neisser C, Erbe A, Jordan R. Nanopatterned polymer brushes by reactive writing. NANOSCALE 2016; 8:7513-22. [PMID: 26902916 DOI: 10.1039/c5nr08282j] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Polymer brush patterns were prepared by a combination of electron beam induced damage in self-assembled monolayers (SAMs), creating a stable carbonaceous deposit, and consecutive self-initiated photografting and photopolymerization (SIPGP). This newly applied technique, reactive writing (RW), is investigated with 1H,1H,2H,2H-perfluorooctyltriethoxysilane SAM (PF-SAM) on silicon oxide, which, when modified by RW, can be selectively functionalized by SIPGP. With the monomer N,N-dimethylaminoethyl methacrylate (DMAEMA), we demonstrate the straightforward formation of polymer brush gradients and single polymer lines of sub-100 nm lateral dimensions, with high contrast to the PF-SAM background. The lithography parameters acceleration voltage, irradiation dose, beam current and dwell time were systematically varied to identify the optimal conditions for the maximum conversion of the SAM into a carbonaceous deposit. The results of this approach were compared to patterns prepared by carbon templating (CT) under analogous conditions, revealing a dwell time dependency, which differs from earlier reports. This new technique expands the range of CT by giving the opportunity to not only vary the chemistry of the created polymer patterns with monomer choice but also vary the chemistry of the surrounding substrate.
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Affiliation(s)
- Jonas F Nawroth
- Chair of Macromolecular Chemistry, School of Science, Technische Universität Dresden, Mommsenstr. 4, 01069 Dresden, Germany.
| | - Claudia Neisser
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - Artur Erbe
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - Rainer Jordan
- Chair of Macromolecular Chemistry, School of Science, Technische Universität Dresden, Mommsenstr. 4, 01069 Dresden, Germany.
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10
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Bao Y, Wen T, Samia ACS, Khandhar A, Krishnan KM. Magnetic Nanoparticles: Material Engineering and Emerging Applications in Lithography and Biomedicine. JOURNAL OF MATERIALS SCIENCE 2016; 51:513-553. [PMID: 26586919 PMCID: PMC4646229 DOI: 10.1007/s10853-015-9324-2] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Accepted: 07/31/2015] [Indexed: 05/05/2023]
Abstract
We present an interdisciplinary overview of material engineering and emerging applications of iron oxide nanoparticles. We discuss material engineering of nanoparticles in the broadest sense, emphasizing size and shape control, large-area self-assembly, composite/hybrid structures, and surface engineering. This is followed by a discussion of several non-traditional, emerging applications of iron oxide nanoparticles, including nanoparticle lithography, magnetic particle imaging, magnetic guided drug delivery, and positive contrast agents for magnetic resonance imaging. We conclude with a succinct discussion of the pharmacokinetics pathways of iron oxide nanoparticles in the human body -- an important and required practical consideration for any in vivo biomedical application, followed by a brief outlook of the field.
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Affiliation(s)
- Yuping Bao
- Chemical and Biological Engineering, The University of Alabama, Tuscaloosa, AL 35487
| | - Tianlong Wen
- State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China
| | | | | | - Kannan M. Krishnan
- Materials Science and Engineering, University of Washington, Seattle, 98195
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11
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Reissner PA, Fedoryshyn Y, Tisserant JN, Stemmer A. Resistive switching of alkanethiolated nanoparticle monolayers patterned by electron-beam exposure. Phys Chem Chem Phys 2016; 18:22783-8. [DOI: 10.1039/c6cp03928f] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Nanoscale structures are fabricated by the direct electron-beam exposure of 10 nm gold nanoparticle monolayers and development in an emulsion. We observe resistive switching in these structures of up to five orders of magnitude.
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Affiliation(s)
| | - Yuriy Fedoryshyn
- ETH Zürich
- Institute of Electromagnetic Fields
- CH-8092 Zürich
- Switzerland
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12
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Rosenberg SG, Barclay M, Fairbrother DH. Electron induced surface reactions of organometallic metal(hfac)₂ precursors and deposit purification. ACS APPLIED MATERIALS & INTERFACES 2014; 6:8590-601. [PMID: 24784352 DOI: 10.1021/am501457h] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The elementary processes associated with electron beam-induced deposition (EBID) and post-deposition treatment of structures created from three metal(II)(hfac)2 organometallic precursors (metal = Pt, Pd, Cu; hfac = CF3C(O)CHC(O)CF3) have been studied using surface analytical techniques. Electron induced reactions of adsorbed metal(II)(hfac)2 molecules proceeds in two stages. For comparatively low electron doses (doses <1 × 10(17) e(-)/cm(2)) decomposition of the parent molecules leads to loss of carbon and oxygen, principally through the formation of carbon monoxide. Fluorine and hydrogen atoms are also lost by electron stimulated C-F and C-H bond cleavage, respectively. Collectively, these processes are responsible for the loss of a significant fraction (≥ 50%) of the oxygen and fluorine atoms, although most (>80%) of the carbon atoms remain. As a result of these various transformations the reduced metal atoms become encased in an organic matrix that is stabilized toward further electron stimulated carbon or oxygen loss, although fluorine and hydrogen can still desorb in the second stage of the reaction under the influence of sustained electron irradiation as a result of C-F and C-H bond cleavage, respectively. This reaction sequence explains why EBID structures created from metal(II)(hfac)2 precursors in electron microscopes contain reduced metal atoms embedded within an oxygen-containing carbonaceous matrix. Except for the formation of copper fluoride from Cu(II)(hfac)2, because of secondary reactions between partially reduced copper atoms and fluoride ions, the chemical composition of EBID films and behavior of metal(II)(hfac)2 precursors was independent of the transition metal's chemical identity. Annealing studies of EBID structures created from Pt(II)(hfac)2 suggest that the metallic character of deposited Pt atoms could be increased by using post deposition annealing or elevated substrate temperatures (>25 °C) during deposition. By exposing EBID structures created from Cu(II)(hfac)2 to atomic oxygen followed by atomic hydrogen, organic contaminants could be abated without annealing.
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Affiliation(s)
- Samantha G Rosenberg
- Department of Chemistry, Johns Hopkins University , Baltimore, Maryland 21218, United States
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13
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Amiaud L, Houplin J, Bourdier M, Humblot V, Azria R, Pradier CM, Lafosse A. Low-energy electron induced resonant loss of aromaticity: consequences on cross-linking in terphenylthiol SAMs. Phys Chem Chem Phys 2014; 16:1050-9. [DOI: 10.1039/c3cp53023j] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Houplin J, Amiaud L, Humblot V, Martin I, Matar E, Azria R, Pradier CM, Lafosse A. Selective terminal function modification of SAMs driven by low-energy electrons (0-15 eV). Phys Chem Chem Phys 2013; 15:7220-7. [PMID: 23558312 DOI: 10.1039/c3cp43750g] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Low-energy electron induced degradation of a model self-assembled monolayer (SAM) of acid terminated alkanethiol was studied under ultra-high vacuum (UHV) conditions at room and low (~40 K) temperatures. Low-energy electron induced chemical modifications of 11-mercaptoundecanoic acid (MUA, HS-(CH2)10-COOH) SAMs deposited on gold were probed in situ as a function of the irradiation energy (<11 eV) by combining two complementary techniques: High Resolution Electron Energy Loss Spectroscopy (HREELS), a surface sensitive vibrational spectroscopy technique, and Electron Stimulated Desorption (ESD) analysis of neutral fragments. The SAM's terminal functions were observed to be selectively damaged at around 1 eV by a resonant electron attachment mechanism, observed to decay by CO, CO2 and H2O formation and desorption. CO2 and H2O were also directly identified at low temperature by vibrational analysis of the irradiated SAMs. At higher irradiation energy, both terminal functions and spacer alkyl chains are damaged upon electron irradiation, by resonant and non-resonant processes.
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Affiliation(s)
- J Houplin
- Université Paris-Sud, Institut des Sciences Moléculaires d'Orsay (ISMO), UMR 8214, Orsay, France
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15
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Wen T, Booth RA, Majetich SA. Ten-nanometer dense hole arrays generated by nanoparticle lithography. NANO LETTERS 2012; 12:5873-5878. [PMID: 23035797 DOI: 10.1021/nl3032372] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Large area dense hole arrays with a feature size of ~10 nm were generated using self-assembled monolayers of nanoparticles as etch masks. To fabricate the hole arrays, monolayers of nanoparticles were irradiated by electron beam to turn surfactants into amorphous carbon, treated by acid to remove the nanoparticle cores, and then etched by CF(4) to deepen the holes. Evaporated gold films preferentially diffuse into the holes to generate gold nanoparticle arrays. However no obvious diffusion into holes was observed for a sputtered iron platinum film.
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Affiliation(s)
- Tianlong Wen
- Physics Department, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
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16
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Nandwana V, Mout R, Yeh YC, Dickert S, Tuominen MT, Rotello VM. Patterning of Protein/Quantum Dot Hybrid Bionanostructures. J Inorg Organomet Polym Mater 2012; 23:227-232. [PMID: 23543831 DOI: 10.1007/s10904-012-9772-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Here we demonstrate patterning of protein/quantum dot hybrid bionanostructures via electrostatic assembly of engineered negatively charged fluorescent protein with positively charged CdSe/ZnS QD patterns formed through e-beam lithography and post-patterning modification with cationic ligands.
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Affiliation(s)
- Vikas Nandwana
- Department of Chemistry, University of Massachusetts Amherst, 710 North Pleasant Street, Amherst, MA 01003, USA
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Habteyes TG, Dhuey S, Wood E, Gargas D, Cabrini S, Schuck PJ, Alivisatos AP, Leone SR. Metallic adhesion layer induced plasmon damping and molecular linker as a nondamping alternative. ACS NANO 2012; 6:5702-5709. [PMID: 22646820 DOI: 10.1021/nn301885u] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Drastic chemical interface plasmon damping is induced by the ultrathin (∼2 nm) titanium (Ti) adhesion layer; alternatively, molecular adhesion is implemented for lithographic fabrication of plasmonic nanostructures without significant distortion of the plasmonic characteristics. As determined from the homogeneous linewidth of the resonance scattering spectrum of individual gold nanorods, an ultrathin Ti layer reduces the plasmon dephasing time significantly, and it reduces the plasmon scattering amplitude drastically. The increased damping rate and decreased plasmon amplitude are due to the dissipative dielectric function of Ti and the chemical interface plasmon damping where the conduction electrons are transferred across the metal-metal interface. In addition, a pronounced red shift due to the Ti adhesion layer, more than predicted using electromagnetic simulation, suggests the prevalence of interfacial reactions. By extending the experiment to conductively coupled ring-rod nanostructures, it is shown that a sharp Fano-like resonance feature is smeared out due to the Ti layer. Alternatively, vapor deposition of (3-mercaptopropyl)trimethoxysilane on gently cleaned and activated lithographic patterns functionalizes the glass surface sufficiently to link the gold nanostructures to the surface by sulfur-gold chemical bonds without observable plasmon damping effects.
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Affiliation(s)
- Terefe G Habteyes
- Department of Chemistry, University of California, Berkeley, California 94720, USA
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18
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Bohrer FI, Covington E, Kurdak Ç, Zellers ET. Characterization of dense arrays of chemiresistor vapor sensors with submicrometer features and patterned nanoparticle interface layers. Anal Chem 2011; 83:3687-95. [PMID: 21500770 DOI: 10.1021/ac200019a] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The performance of arrays of small, densely integrated chemiresistor (CR) vapor sensors with electron-beam patterned interface layers of thiolate-monolayer-protected gold nanoparticles (MPNs) is explored. Each CR in the array consists of a 100-μm(2) interdigital electrode separated from adjacent devices by 4 μm. Initial studies involved four separate arrays, each containing four CRs coated with one of four different MPNs, which were calibrated with five vapors before and after MPN-film patterning. MPNs derived from n-octanethiol (C8), 4-(phenylethynyl)-benzenethiol (DPA), 6-phenoxyhexane-1-thiol (OPH), and methyl-6-mercaptohexanoate (HME) were tested. Parallel calibrations of MPN-coated thickness-shear-mode resonators (TSMR) were used to derive partition coefficients of unpatterned films and to assess transducer-dependent factors affecting responses. A 600-μm(2) 4-CR array with four different patterned MPN interface layers, in which the MPN derived from 7-hydroxy-7,7-bis(trifluoro-methyl)heptane-1-thiol (HFA) was substituted for HME, was then characterized. This is the smallest multi-MPN array yet reported. Reductions in the diversity of the collective response patterns are observed with the patterned films, but projected vapor discrimination rates remain high. The use of such arrays as ultralow-dead-volume detectors in microscale gas chromatographic analyzers is discussed.
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Affiliation(s)
- Forest I Bohrer
- Center for Wireless Integrated Microsystems, Department of Environmental Health Sciences, University of Michigan, Ann Arbor, Michigan 48109-2029, USA
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19
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Nandwana V, Subramani C, Yeh YC, Yang B, Dickert S, Barnes MD, Tuominen MT, Rotello VM. Direct patterning of quantum dot nanostructures via electron beam lithography. ACTA ACUST UNITED AC 2011. [DOI: 10.1039/c1jm11782c] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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20
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Covington E, Bohrer FI, Xu C, Zellers ET, Kurdak C. Densely integrated array of chemiresistor vapor sensors with electron-beam patterned monolayer-protected gold nanoparticle interface films. LAB ON A CHIP 2010; 10:3058-3060. [PMID: 20927431 DOI: 10.1039/c0lc00071j] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Use of electron-beam induced crosslinking to pattern films of monolayer-protected gold nanoparticles (MPNs) onto a chemiresistor (CR) sensor array is described. Each of the four CRs comprises a 100 µm(2) set of interdigital electrodes (IDEs) with 100 nm widths and spaces, separated from adjacent devices by 4 µm. Films of four MPNs, each with a different thiolate monolayer, were successively patterned on the IDEs. Vapor exposures yield rapid, reversible changes in CR resistances and differential vapor sensitivities comparable to those reported for larger CRs with unpatterned MPN films. The array response patterns facilitate vapor discrimination. This is the smallest MPN-coated CR array yet reported. The advantages of using such an array as the detector in microfabricated gas chromatographic analyzers are considered.
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Affiliation(s)
- E Covington
- Department of Physics, University of Michigan, Ann Arbor, MI 48109, USA
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21
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Fudickar W, Linker T. Photoimaging with singlet oxygen at the solid-air interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:9797-9803. [PMID: 19441843 DOI: 10.1021/la9008976] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Films of anthracene carboxylic acids were irradiated through photomasks and oxidized at the exposed regions by singlet oxygen upon sensitization. The efficiency of a photomask to protect the material underneath was investigated by optical and infrared spectroscopy. As the thickness of the film is reduced, the efficiency of the mask drops. This is explained by the migration of singlet oxygen at the solid-air interface, which in turn reacts at the masked area. For films with a thickness of <15 nm, the efficiency of the mask approaches zero; sufficient efficiency is achieved at thicknesses > 100 nm. From the investigations, it will become clear that the contrast between the irradiated and masked area of an image is affected by reduction of the film thickness. On the other hand, the resolution of an image, which relates to the minimum feature size of an image, is not dependent on the thickness of the film. The contributions of "inside" and "outside" reactions are examined separately, and a quantitative approximation of the spatial range of both modes of the oxygenation is given. We set up an approximate relation between mask efficiency and experimental conditions comprising internal and external oxygen diffusion, film thickness, and mask dimensions. These results give a deeper insight into the limits of resolution and contrast in singlet oxygen lithography.
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Affiliation(s)
- Werner Fudickar
- Department of Chemistry, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam/Golm, Germany
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22
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Bhuvana T, Gregoratti L, Heun S, Dalmiglio M, Kulkarni GU. Electron resist behavior of Pd hexadecanethiolate examined using X-ray photoelectron spectroscopy with nanometric lateral resolution. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:1259-1264. [PMID: 19093756 DOI: 10.1021/la803344f] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Electron resist behavior of Pd hexadecanethiolate is studied by varying the e-dosage from 2-280 muC.cm(-2). The e-beam exposed resist is characterized using energy dispersive spectroscopy, infrared spectroscopy, and X-ray photoelectron spectroscopy with nanometric lateral resolution. Electron beam exposure causes defects in the alkyl chain of the thiolate, giving the required solubility contrast during the developing step, thus qualifying the precursor as an e-beam resist. On exposure to the e-beam, the reduction of Pd(2+) to Pd(0) is observed, and the reduction increases with increasing e-dosage. The resist is highly sensitive, with the estimated sensitivity being 32 muC.cm(-2). Thermolysis at 250 degrees C leads to the formation of Pd nanoparticles, demonstrating the essential feature of a direct write resist for conducting patterns.
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Affiliation(s)
- T Bhuvana
- Chemistry and Physics of Materials Unit and DST Unit on Nanoscience, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P O, Bangalore 560 064, India
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23
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Self-assembled monolayers of poly(ethylene glycol) siloxane as a resist for ultrahigh-resolution electron beam lithography on silicon oxide. ACTA ACUST UNITED AC 2009. [DOI: 10.1116/1.3212899] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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24
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Garand E, Moula MG, Rowntree PA. Localization vs conduction: anionic excitations in alkanethiol self-assembled monolayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:13850-13854. [PMID: 19360932 DOI: 10.1021/la803036v] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Low-energy (6-11 eV) electron injection into Xe-coated self-assembled alkanethiol monolayers (SAMs) is reported. At most energies, the presence of the Xe film has negligible effect on the incident electrons, which penetrate the overlayer and induce significant C--H bond rupture at the terminal methyl sites and the subsurface methylene sites of the organic substrates. However, irradiation at 7.7 +/- 0.2 eV can lead to resonant electronic excitations of the Xe adsorbates to create transient anionic states in the Xe overlayer. Transfer of anionic excitations from the Xe overlayer to the SAM initially prepares excited anionic states at the terminal CH3 groups and leads to highly selective dissociations at the methyl sites, with negligible conduction along the alkane chain which would lead to subsurface C-H bond rupture at the methylene sites. These results demonstrate that the mobility of electronically excited charged states along the alkanethiol chains is significantly less than that of simple excess electrons and that highly site-selective chemical modifications can be induced by low-energy electrons in these highly homogeneous organic films.
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Affiliation(s)
- Etienne Garand
- Department of Chemistry, University of Guelph, Guelph, Ontario, Canada N1G 2W1
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25
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Mullen TJ, Zhang P, Srinivasan C, Horn MW, Weiss PS. Combining electrochemical desorption and metal deposition on patterned self-assembled monolayers. J Electroanal Chem (Lausanne) 2008. [DOI: 10.1016/j.jelechem.2007.11.038] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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26
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Bhuvana T, Kulkarni GU. A SERS-active nanocrystalline pd substrate and its nanopatterning leading to biochip fabrication. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2008; 4:670-676. [PMID: 18491365 DOI: 10.1002/smll.200701075] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Nanocrystalline metallic Pd films have been produced by thermolysis of Pd hexadecanethiolate deposited on a Si surface. The particle size was in the range of 50-60 nm based on electron and atomic force microscopy. The Pd surface produced was found to be surface-enhanced Raman scattering (SERS) active with an enhancement factor of approximately 10(5). The electron-resist behavior of Pd thiolate is exploited in conceptualizing a prototype chip with patterned Pd regions that are SERS active, called "SERS bits", which host different biomolecules.
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Affiliation(s)
- Thiruvelu Bhuvana
- Chemistry and Physics of Materials Unit and DST Unit on Nanoscience Jawaharlal Nehru Centre for Advanced Scientific Research Jakkur P O, Bangalore 560 064, India
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27
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Bhuvana T, Kulkarni GU. Highly conducting patterned Pd nanowires by direct-write electron beam lithography. ACS NANO 2008; 2:457-462. [PMID: 19206570 DOI: 10.1021/nn700372h] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Palladium hexadecylthiolate is shown to serve as a negative-tone direct-write electron resist to produce nanopatterns down to 30 nm. The written patterns do not deviate much from the precursor in composition, while a post-treatment at 230 degrees C in air produced metallic Pd nanowires with residual carbon less than 10% and resistivity close to the bulk value, a desirable property of interconnects in nanocircuitry. The as-written patterns contain small nanocrystals (<5 nm) in a hydrocarbon matrix, which upon annealing aggregate to form well-connected networks of larger nanocrystals (5-15 nm), thus giving rise to metallic conductivity.
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Affiliation(s)
- T Bhuvana
- Chemistry and Physics of Materials Unit and DST Unit on Nanoscience, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur PO, Bangalore 560 064, India
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28
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Srinivasan C, Mullen TJ, Hohman JN, Anderson ME, Dameron AA, Andrews AM, Dickey EC, Horn MW, Weiss PS. Scanning electron microscopy of nanoscale chemical patterns. ACS NANO 2007; 1:191-201. [PMID: 19206649 DOI: 10.1021/nn7000799] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A series of nanoscale chemical patterning methods based on soft and hybrid nanolithographies have been characterized using scanning electron microscopy with corroborating evidence from scanning tunneling microscopy and lateral force microscopy. We demonstrate and discuss the unique advantages of the scanning electron microscope as an analytical tool to image chemical patterns of molecules highly diluted within a host self-assembled monolayer and to distinguish regions of differential mass coverage in patterned self-assembled monolayers. We show that the relative contrast of self-assembled monolayer patterns in scanning electron micrographs depends on the operating primary electron beam voltage, monolayer composition, and monolayer order, suggesting that secondary electron emission and scattering can be used to elucidate chemical patterns.
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Affiliation(s)
- Charan Srinivasan
- Departments of Chemistry and Physics, The Pennsylvania State University, University Park, PA 16802-6300, USA
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29
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Affiliation(s)
- Feng Tao
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA
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30
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Chua LL, Dipankar M, Sivaramakrishnan S, Gao X, Qi D, Wee ATS, Ho PKH. Large damage threshold and small electron escape depth in X-ray absorption spectroscopy of a conjugated polymer thin film. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:8587-94. [PMID: 16981780 DOI: 10.1021/la060974q] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The information depth of near-edge X-ray absorption fine structure spectroscopy in the total electron yield mode (TEY-NEXAFS) is given by the escape depth of the TEY electrons z(TEY). This is determined by the effective ranges both of the inelastically scattered secondary electrons and of the primary excited electron before they thermalize below the vacuum level. For regioregular poly(3-hexylthiophene) (rreg-P3HT) thin films, we have measured the total electron emission efficiency to be 0.028 +/- 0.005 e/ph at an incident photon energy of 320 eV. The range of the primary electron was computed using optical dielectric-loss theory to be 7.5 nm. The range of the secondary electrons was then found by modeling to be 3.0 nm. This gives z(TEY) to be 2.5 nm, which is considerably less than the often-assumed value of 10 nm in the literature. It is also considerably smaller than the computed electron-electron scattering inelastic mean free path in the material, which suggests the predominance of electron-phonon scattering. Thus, TEY-NEXAFS has sufficient surface sensitivity to probe the frontier molecular layers of these organic conjugated polymers. In a second aspect of this report, the rreg-P3HT films have been characterized by in-situ core and valence photoemission spectroscopies and by ex-situ microattenuated total-reflection vibrational spectroscopy as a function of irradiation dose. No damage was observed in composition, bonding, orientation, and surface morphology under typical TEY-NEXAFS spectral acquisition conditions. For an integrated TEY that exceeds 2 x 10(-3) C cm(-2), however, the material degrades via alkyl side-chain dehydrogenation to unsaturated units, cross linking, ring opening of the backbone, and sulfur extrusion. Given that secondary electrons are the dominant cause of radiation damage, this exposure threshold measured by integrated TEY should also be valid at other X-ray energies.
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Affiliation(s)
- Lay-Lay Chua
- Department of Physics, National University of Singapore, Lower Kent Ridge Road, Singapore 117542.
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31
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Weng CC, Liao JD, Wu YT, Wang MC, Klauser R, Zharnikov M. Modification of Monomolecular Self-Assembled Films by Nitrogen−Oxygen Plasma. J Phys Chem B 2006; 110:12523-9. [PMID: 16800581 DOI: 10.1021/jp060572r] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The modification of octadecanethiolate self-assembled monolayers on Au and Ag by nitrogen-oxygen downstream microwave plasma with variable oxygen content (up to 1%) has been studied by synchrotron-based high-resolution X-ray photoelectron spectroscopy. The primary processes were dehydrogenation, desorption of hydrocarbon and sulfur-containing species, and the oxidation of the alkyl matrix and headgroup-substrate interface. The exact character and the rates of the plasma-induced changes were found to be dependent on the substrate and plasma composition, with the processes in the aliphatic matrix and headgroup-substrate interface being mostly decoupled. In particular, the rates of all major plasma-induced processes were found to be directly proportional to the oxygen content in the plasma, which can be, thus, considered as a measure of the plasma reactivity. Along with the character of the observed changes, exhibiting a clear dominance of the oxidative processes, this suggests that the major effect of the oxygen-nitrogen downstream microwave plasma is provided by reactive oxygen-derived species in the downstream region, viz. long-living oxygen radicals and metastable species.
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Affiliation(s)
- Chih-Chiang Weng
- Department of Materials Science and Engineering, National Cheng Kung University, No. 1, University Road, Tainan 70101, Taiwan
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32
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Richter AG, Guico R, Shull K, Wang J. Thickness and Interfacial Roughness Changes in Polymer Thin Films during X-Irradiation. Macromolecules 2006. [DOI: 10.1021/ma050060v] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Andrew G. Richter
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, and Department of Materials Science, Northwestern University, Evanston, Illinois 60208
| | - Rodney Guico
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, and Department of Materials Science, Northwestern University, Evanston, Illinois 60208
| | - Ken Shull
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, and Department of Materials Science, Northwestern University, Evanston, Illinois 60208
| | - Jin Wang
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, and Department of Materials Science, Northwestern University, Evanston, Illinois 60208
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Deering AL, Van Lue SM, Kandel SA. Ambient-pressure vapor deposition of octanethiol self-assembled monolayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:10260-3. [PMID: 16262271 DOI: 10.1021/la050814z] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Scanning tunneling microscopy was used to characterize self-assembled monolayers (SAMs) of octanethiol on Au(111), created using vapor deposition at elevated temperatures and ambient pressure. Monolayers contained large, close-packed ( radical3 x radical3)R30 degrees domains with sizes considerably larger than those typically formed from conventional solution-phase preparation and with crystallographically straight domain boundaries. New striped surface phases were also observed, including a 13 x radical3 phase with a density that was 69% of the close-packed density; these striped phases appeared topographically higher in STM images than close-packed monolayers.
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Ye T, McArthur EA, Borguet E. Mechanism of UV Photoreactivity of Alkylsiloxane Self-Assembled Monolayers. J Phys Chem B 2005; 109:9927-38. [PMID: 16852200 DOI: 10.1021/jp0474273] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
A molecular level understanding of the photoreactivity of self-assembled monolayers (SAMs) becomes increasingly important as the spatial resolution starts to be limited by the size of the resist and the spatial extent of the photochemical reactions in photoresist micropatterning. To this end, a number of surface characterization techniques were combined to understand the reactive agents, reactive sites, kinetics, and reaction pathways in the UV photoreactivity of octadecylsiloxane (ODS) SAMs. Quantitative analysis of our results provides evidence that ground state atomic oxygen is the primary reactive agent for the UV degradation of ODS SAMs. UV degradation, which follows zero-order kinetics, results in the scission of alkyl chains instead of the siloxane headgroups. Our results suggest that the top of the ODS SAMs is the preferential reactive site. Using a novel, highly surface sensitive technique, fluorescence labeling of surface species, we identified the presence of submonolayer quantities chemical functional groups formed by the UV degradation. These groups are intermediates in a proposed mechanism based on hydrogen abstraction.
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Affiliation(s)
- Tao Ye
- Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122, USA
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35
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Cyganik P, Vandeweert E, Postawa Z, Bastiaansen J, Vervaecke F, Lievens P, Silverans RE, Winograd N. Modification and Stability of Aromatic Self-Assembled Monolayers upon Irradiation with Energetic Particles. J Phys Chem B 2005; 109:5085-94. [PMID: 16863170 DOI: 10.1021/jp0478209] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We have studied ion and electron irradiation of self-assembled monolayers (SAMs) of 2-(4'-methyl-biphenyl-4yl)-ethanethiol (BP2, CH3-C6H4C6H4CH2CH2-SH), phenyl mercaptan (PEM, C6H5CH2CH2-SH), and 4'-methyl-biphenyl-4-thiol (BP0, CH3-C6H4C6H4-SH) deposited on Au(111) substrates. Desorption of neutral particles from PEM/Au and BP2/Au was investigated using laser ionization in combination with mass spectrometry. The ion-induced damage of both BP2 and PEM SAMs is very efficient and interaction with a single ion leads to the modification of tens of molecules. This feature is the result of a desorption process caused by a chemical reaction initiated by an ion impact. Both for ions and electrons, experiments indicate that the possibility for scission of the Au-S bond strongly depends on the chemical nature of the SAM system. We attribute the possible origin of this effect to the orientation of the Au-S-C angle or adsorption sites of molecules. The analysis of electron-irradiated PEM/Au and BP2/Au, using ion-initiated laser probing, enabled measurements of the cross section for the electron-induced damage of the intact molecule or specific fragment. Analysis of electron-irradiated BP0/Au by using time-of-flight secondary ion mass spectrometry (TOF-SIMS) provides direct evidence for the quasi-polymerization process induced by electron irradiation.
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Affiliation(s)
- P Cyganik
- Smoluchowski Institute of Physics, Jagiellonian University, ul. Reymonta 4, PL 30-059 Kraków, Poland.
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36
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Mendes PM, Preece JA. Precision chemical engineering: integrating nanolithography and nanoassembly. Curr Opin Colloid Interface Sci 2004. [DOI: 10.1016/j.cocis.2004.06.005] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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37
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Shaporenko A, Adlkofer K, Johansson LSO, Ulman A, Grunze M, Tanaka M, Zharnikov M. Spectroscopic Characterization of 4‘-Substituted Aromatic Self-Assembled Monolayers on GaAs(100) Surface. J Phys Chem B 2004. [DOI: 10.1021/jp040474a] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- A. Shaporenko
- Angewandte Physikalische Chemie, Universität Heidelberg, Im Neuenheimer Feld 253, D-69120 Heidelberg, Germany, Lehrstuhl für Biophysik E22, Technische Universität München, James-Franck-Strasse, D-85748, Garching, Germany, Department of Physics, Karlstad University, Universitetsgatan 1, S-65188 Karlstad, Sweden, and Department of Chemistry and the NSF MRSEC for Polymers at Engineered Interfaces, Polytechnic University, Brooklyn, New York 11201
| | - K. Adlkofer
- Angewandte Physikalische Chemie, Universität Heidelberg, Im Neuenheimer Feld 253, D-69120 Heidelberg, Germany, Lehrstuhl für Biophysik E22, Technische Universität München, James-Franck-Strasse, D-85748, Garching, Germany, Department of Physics, Karlstad University, Universitetsgatan 1, S-65188 Karlstad, Sweden, and Department of Chemistry and the NSF MRSEC for Polymers at Engineered Interfaces, Polytechnic University, Brooklyn, New York 11201
| | - L. S. O. Johansson
- Angewandte Physikalische Chemie, Universität Heidelberg, Im Neuenheimer Feld 253, D-69120 Heidelberg, Germany, Lehrstuhl für Biophysik E22, Technische Universität München, James-Franck-Strasse, D-85748, Garching, Germany, Department of Physics, Karlstad University, Universitetsgatan 1, S-65188 Karlstad, Sweden, and Department of Chemistry and the NSF MRSEC for Polymers at Engineered Interfaces, Polytechnic University, Brooklyn, New York 11201
| | - A. Ulman
- Angewandte Physikalische Chemie, Universität Heidelberg, Im Neuenheimer Feld 253, D-69120 Heidelberg, Germany, Lehrstuhl für Biophysik E22, Technische Universität München, James-Franck-Strasse, D-85748, Garching, Germany, Department of Physics, Karlstad University, Universitetsgatan 1, S-65188 Karlstad, Sweden, and Department of Chemistry and the NSF MRSEC for Polymers at Engineered Interfaces, Polytechnic University, Brooklyn, New York 11201
| | - M. Grunze
- Angewandte Physikalische Chemie, Universität Heidelberg, Im Neuenheimer Feld 253, D-69120 Heidelberg, Germany, Lehrstuhl für Biophysik E22, Technische Universität München, James-Franck-Strasse, D-85748, Garching, Germany, Department of Physics, Karlstad University, Universitetsgatan 1, S-65188 Karlstad, Sweden, and Department of Chemistry and the NSF MRSEC for Polymers at Engineered Interfaces, Polytechnic University, Brooklyn, New York 11201
| | - M. Tanaka
- Angewandte Physikalische Chemie, Universität Heidelberg, Im Neuenheimer Feld 253, D-69120 Heidelberg, Germany, Lehrstuhl für Biophysik E22, Technische Universität München, James-Franck-Strasse, D-85748, Garching, Germany, Department of Physics, Karlstad University, Universitetsgatan 1, S-65188 Karlstad, Sweden, and Department of Chemistry and the NSF MRSEC for Polymers at Engineered Interfaces, Polytechnic University, Brooklyn, New York 11201
| | - M. Zharnikov
- Angewandte Physikalische Chemie, Universität Heidelberg, Im Neuenheimer Feld 253, D-69120 Heidelberg, Germany, Lehrstuhl für Biophysik E22, Technische Universität München, James-Franck-Strasse, D-85748, Garching, Germany, Department of Physics, Karlstad University, Universitetsgatan 1, S-65188 Karlstad, Sweden, and Department of Chemistry and the NSF MRSEC for Polymers at Engineered Interfaces, Polytechnic University, Brooklyn, New York 11201
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Eah SK, Jaeger HM, Scherer NF, Lin XM, Wiederrecht GP. Femtosecond transient absorption dynamics of close-packed gold nanocrystal monolayer arrays. Chem Phys Lett 2004. [DOI: 10.1016/j.cplett.2004.01.056] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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39
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Klauser R, Hong IH, Wang SC, Zharnikov M, Paul A, Gölzhäuser A, Terfort A, Chuang TJ. Imaging and Patterning of Monomolecular Resists by Zone-Plate-Focused X-ray Microprobe. J Phys Chem B 2003. [DOI: 10.1021/jp0307396] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | | | | | | | | | | | - A. Terfort
- Anorganische und Angewandte Chemie, Universität Hamburg, 20146 Hamburg, Germany
| | - T. J. Chuang
- Center for Condensed Matter Sciences, National Taiwan University, Taipei 106, Taiwan
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40
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Huels MA, Dugal PC, Sanche L. Degradation of functionalized alkanethiolate monolayers by 0–18 eV electrons. J Chem Phys 2003. [DOI: 10.1063/1.1574791] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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41
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Wang MC, Liao JD, Weng CC, Klauser R, Frey S, Zharnikov M, Grunze M. The Effect of the Substrate on Response of Thioaromatic Self-Assembled Monolayers to Free Radical-Dominant Plasma. J Phys Chem B 2002. [DOI: 10.1021/jp014166d] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ming-Chen Wang
- Department of Biomedical Engineering, Chung Yuan Christian University, 22, Pu-Jen, Pu−Chung-Li, Chung-Li, Taoyuan 32023, Taiwan (ROC), Department of Materials Science and Engineering, National Cheng Kung University, No. 1, University Road, Tainan 701, Taiwan (ROC), Synchrotron Radiation Research Center, No. 1 R&D Road VI, Hsinchu Science-Based Industrial Park, Hsinchu 300, Taiwan (ROC), and Angewandte Physikalische Chemie, Universität Heidelberg, Im Neuenheimer Feld 253, 69120 Heidelberg, Germany
| | - Jiunn-Der Liao
- Department of Biomedical Engineering, Chung Yuan Christian University, 22, Pu-Jen, Pu−Chung-Li, Chung-Li, Taoyuan 32023, Taiwan (ROC), Department of Materials Science and Engineering, National Cheng Kung University, No. 1, University Road, Tainan 701, Taiwan (ROC), Synchrotron Radiation Research Center, No. 1 R&D Road VI, Hsinchu Science-Based Industrial Park, Hsinchu 300, Taiwan (ROC), and Angewandte Physikalische Chemie, Universität Heidelberg, Im Neuenheimer Feld 253, 69120 Heidelberg, Germany
| | - Chih-Chiang Weng
- Department of Biomedical Engineering, Chung Yuan Christian University, 22, Pu-Jen, Pu−Chung-Li, Chung-Li, Taoyuan 32023, Taiwan (ROC), Department of Materials Science and Engineering, National Cheng Kung University, No. 1, University Road, Tainan 701, Taiwan (ROC), Synchrotron Radiation Research Center, No. 1 R&D Road VI, Hsinchu Science-Based Industrial Park, Hsinchu 300, Taiwan (ROC), and Angewandte Physikalische Chemie, Universität Heidelberg, Im Neuenheimer Feld 253, 69120 Heidelberg, Germany
| | - Ruth Klauser
- Department of Biomedical Engineering, Chung Yuan Christian University, 22, Pu-Jen, Pu−Chung-Li, Chung-Li, Taoyuan 32023, Taiwan (ROC), Department of Materials Science and Engineering, National Cheng Kung University, No. 1, University Road, Tainan 701, Taiwan (ROC), Synchrotron Radiation Research Center, No. 1 R&D Road VI, Hsinchu Science-Based Industrial Park, Hsinchu 300, Taiwan (ROC), and Angewandte Physikalische Chemie, Universität Heidelberg, Im Neuenheimer Feld 253, 69120 Heidelberg, Germany
| | - Stefan Frey
- Department of Biomedical Engineering, Chung Yuan Christian University, 22, Pu-Jen, Pu−Chung-Li, Chung-Li, Taoyuan 32023, Taiwan (ROC), Department of Materials Science and Engineering, National Cheng Kung University, No. 1, University Road, Tainan 701, Taiwan (ROC), Synchrotron Radiation Research Center, No. 1 R&D Road VI, Hsinchu Science-Based Industrial Park, Hsinchu 300, Taiwan (ROC), and Angewandte Physikalische Chemie, Universität Heidelberg, Im Neuenheimer Feld 253, 69120 Heidelberg, Germany
| | - Michael Zharnikov
- Department of Biomedical Engineering, Chung Yuan Christian University, 22, Pu-Jen, Pu−Chung-Li, Chung-Li, Taoyuan 32023, Taiwan (ROC), Department of Materials Science and Engineering, National Cheng Kung University, No. 1, University Road, Tainan 701, Taiwan (ROC), Synchrotron Radiation Research Center, No. 1 R&D Road VI, Hsinchu Science-Based Industrial Park, Hsinchu 300, Taiwan (ROC), and Angewandte Physikalische Chemie, Universität Heidelberg, Im Neuenheimer Feld 253, 69120 Heidelberg, Germany
| | - Michael Grunze
- Department of Biomedical Engineering, Chung Yuan Christian University, 22, Pu-Jen, Pu−Chung-Li, Chung-Li, Taoyuan 32023, Taiwan (ROC), Department of Materials Science and Engineering, National Cheng Kung University, No. 1, University Road, Tainan 701, Taiwan (ROC), Synchrotron Radiation Research Center, No. 1 R&D Road VI, Hsinchu Science-Based Industrial Park, Hsinchu 300, Taiwan (ROC), and Angewandte Physikalische Chemie, Universität Heidelberg, Im Neuenheimer Feld 253, 69120 Heidelberg, Germany
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42
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Modification of thiol-derived self-assembling monolayers by electron and x-ray irradiation: Scientific and lithographic aspects. ACTA ACUST UNITED AC 2002. [DOI: 10.1116/1.1514665] [Citation(s) in RCA: 238] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Liao JD, Wang MC, Weng CC, Klauser R, Frey S, Zharnikov M, Grunze M. Modification of Alkanethiolate Self-Assembled Monolayers by Free Radical-Dominant Plasma. J Phys Chem B 2001. [DOI: 10.1021/jp011119c] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | | | | | - Ruth Klauser
- Synchrotron Radiation Research Center, No. 1 R&D Road VI, Hsinchu Science-Based Industrial Park, Hsinchu 300, Taiwan (ROC)
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44
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Han SM, Ashurst WR, Carraro C, Maboudian R. Formation of alkanethiol monolayer on Ge(111). J Am Chem Soc 2001; 123:2422-5. [PMID: 11456892 DOI: 10.1021/ja993816c] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Alkanethiols, CH3(CH2)(n-1)SH, are shown to react readily with HF-treated Ge(111) surface at room temperature to form a high-quality monolayer. The resulting films are characterized by using contact angle analysis (CAA), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), spectroscopic ellipsometry (SE), and high-resolution electron energy loss spectroscopy (HREELS). The octanethiol and octadecanethiol films on Ge(111) both exhibit 101 degrees and 40 degrees water and hexadecane contact angles, respectively. These values indicate that the thiol surface coverage is relatively high, and that the films possess a high degree of orientational ordering. The angle-resolved XPS analysis supports that thiols are bound to the Ge surface by Ge-S bonds at the monolayer/Ge interface. The film thickness values obtained by XPS and SE agree well with the earlier reported values on alkyl monolayers on Ge(111) prepared by Grignard reaction. On the basis of HREEL spectra taken after thermal annealing steps, the monolayers are found to be thermally stable up to 450 K. The thermal stability provides further evidence that thiols are covalently bonded to Ge(111).
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Affiliation(s)
- S M Han
- Contribution from the Department of Chemical Engineering, University of California, Berkeley, California 94720, USA
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45
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Werst DW, Vinokur EI. Radiation Damage of Alkoxy and Siloxy Ligands Bonded to Silica. J Phys Chem B 2001. [DOI: 10.1021/jp003806u] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- D. W. Werst
- Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439
| | - E. I. Vinokur
- Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439
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Kim TK, Yang XM, Peters RD, Sohn BH, Nealey PF. Chemical Modification of Self-Assembled Monolayers by Exposure to Soft X-rays in Air. J Phys Chem B 2000. [DOI: 10.1021/jp000145s] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Tae K. Kim
- Department of Chemical Engineering and Center for Nanotechnology, University of Wisconsin, Madison, Wisconsin 53706
| | - Xiao M. Yang
- Department of Chemical Engineering and Center for Nanotechnology, University of Wisconsin, Madison, Wisconsin 53706
| | - Richard D. Peters
- Department of Chemical Engineering and Center for Nanotechnology, University of Wisconsin, Madison, Wisconsin 53706
| | - B. H. Sohn
- Department of Chemical Engineering and Center for Nanotechnology, University of Wisconsin, Madison, Wisconsin 53706
| | - Paul F. Nealey
- Department of Chemical Engineering and Center for Nanotechnology, University of Wisconsin, Madison, Wisconsin 53706
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Bumm LA, Arnold JJ, Charles LF, Dunbar TD, Allara DL, Weiss PS. Directed Self-Assembly to Create Molecular Terraces with Molecularly Sharp Boundaries in Organic Monolayers. J Am Chem Soc 1999. [DOI: 10.1021/ja982157l] [Citation(s) in RCA: 119] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- L. A. Bumm
- Contribution from the Departments of Chemistry and Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802-6300
| | - J. J. Arnold
- Contribution from the Departments of Chemistry and Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802-6300
| | - L. F. Charles
- Contribution from the Departments of Chemistry and Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802-6300
| | - T. D. Dunbar
- Contribution from the Departments of Chemistry and Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802-6300
| | - D. L. Allara
- Contribution from the Departments of Chemistry and Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802-6300
| | - P. S. Weiss
- Contribution from the Departments of Chemistry and Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802-6300
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50
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Patterning of octadecylsiloxane self-assembled monolayers on Si(100) using Ar([sup 3]P[sub 0,2]) atoms. ACTA ACUST UNITED AC 1999. [DOI: 10.1116/1.590699] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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