Symposium Organizers
Daryush Ila Alabama A&M University
John Baglin IBM Almaden Research Center
Naoki Kishimoto National Institute for Materials Science
Paul K. Chu City University of Hong Kong
GG1: Ion Beam Nanofab: Tools and Techniques
Session Chairs
John Baglin
Robert Zimmerman
Tuesday PM, April 10, 2007
Room 3016 (Moscone West)
9:45 AM - **GG1.1
Ion-Beam Projection Techniques for Nanometer-Scale Patterning
Ka-Ngo Leung 1 2
1 Plasma and Ion Source Technology Group,, Lawrence Berkeley National Laboratory, Berkeley, California, United States, 2 Nuclear Engineering Department, University of California, Berkeley, California, United States
Show AbstractMaskless ion beam lithography schemes have been investigated at Lawrence Berkeley National Laboratory (LBNL) for future integrated circuit manufacturing, thin film media patterning, and micromachining. The Maskless Micro-Ion-Beam Reduction Lithography (MMRL) system completely eliminates the first stage of the conventional IPL tool that contains the ion beam illumination column before the stencil mask and the mask itself. It consists of an RF-driven multicusp source capable of producing large area of uniform plasma, a multi-beamlet pattern generator, and an all-electrostatic ion optical column. Eliminating the stencil mask from the lithographic process would result in enormous cost savings. The use of an electronic pattern generator would also offer improved flexibility for rapid implementation of new designs and higher throughputs due to time savings from the elimination of multiple mask steps. We have performed exposure study on PMMA and Shipley UVII-HS resists by using 75 keV H+ or He+ ion beams. Tremendous effort has been spent to improve the resolution, including the use of a limiting aperture, eliminating the dc magnetic field effect and minimizing impurity ions. Feature size smaller than 50 nm has been achieved on PMMA resist exposures. Micro-beam extraction and switching through a multi-layer array of nine 50 micro-apertures together with 10X reduction have been demonstrated. Different pattern generator configurations are being investigated so as to demonstrate maskless ion beam projection lithography.* This work was supported by DARPA and the U.S. Dept. of Energy under Contract No. DE-AC02-05CH11231.
10:15 AM - **GG1.2
Cluster Ion Beam Process for Nanofabrication.
Isao Yamada 1 , Noriaki Toyoda 2
1 Laboratory of Advanced Science & Technology for Industry, University of Hyogo, Ako Japan, 2 Laboratory of Advanced Science & Technology for Industry, University of Hyogo, Ako Japan
Show AbstractThis paper reviews the development of gas cluster ion beam (GCIB) technology, including the generation of cluster beams, fundamental characteristics of cluster ion to solid surface interactions, emerging industrial applications, and identification of some of the significant events which occurred as the technology has evolved into what it is today. More than 20 years have passed since the author first began to explore feasibility of processing by gas cluster ion beams at the Ion Beam Engineering Experimental Laboratory of Kyoto University. Processes employing ions of gaseous material clusters comprised of a few hundred to many thousand atoms are now being developed into a new field of ion beam technology. Cluster-surface collisions produce important non-linear effects which are being applied to shallow junction formation, to etching and smoothing of semiconductors, metals, and dielectrics, to assisted formation of thin films with nano-scale accuracy, and to other surface modification applications. Initial research on gas cluster beam formation showed that supersonic nozzles having converging-diverging shapes operating at room temperature could produce intense beams of gas clusters. This then led to research and development of gas cluster ion beam (GCIB) techniques and to investigations of new ion-solid interactions produced by gas cluster ion impacts. These studies demonstrated that GCIB produces unique ion/solid interactions and offers new atomic and molecular ion beam process opportunities in areas of implantation, sputtering, and ion beam assisted deposition. Over the first 10 years of GCIB studies, low energy surface interaction effects, lateral sputtering phenomena and high chemical reaction effects were observed experimentally and were explained by means of molecular dynamics (MD) modeling. In 2000, a four year R&D project for development of GCIB industrial technology began in Japan under funding from the New Energy and Industrial Technology Development Organization (NEDO). This project involved subjects in areas of semiconductor surface processing, high accuracy surface processing and high-quality film formation. The project was supported by the formation of a new Collaborative Research Center of Cluster Ion Beam Technology at Kyoto University and University of Hyogo.In 2002, another major GCIB project which emphasized nano-technology applications was started under a contract from the Ministry of Economy and Technology for Industry (METI). This METI project currently involves development related to size-selected cluster ion beam equipment and processes, and development of GCIB processes for very high rate etching and for zero damage etching of magnetic materials and compound semiconductor materials.
10:45 AM - GG1.3
Nanoscale Nano-systems by MeV Ion Beam
Daryush Ila 1 , S. Budak 1 , B. Zheng 1 , R. Zimmerman 1 , C. Muntele 1
1 Center for Irradiation Materials, Alabama A&M University, Normal, Alabama, United States
Show Abstract We have used MeV ion beam to form Nanolayers of Nanocrystals of various materials within a selected host materials. The layered structure was produced by sequentially co-depositing host along with selected species and the host alone. We have observed that the Nanocrystals are formed along the direction of MeV Ion beam passage due to the electronic ionization of substrate. One system consist of Nanolayers (Quantum Well) of Nano-Crystals (Quantum Dots) to generate optical filters (OF) with variable window as well as highly efficient thermoelectric generators (TEG). To generate highly efficient TEG we had to enhance the electrically conductive as well as the thermal insulation and increase the Seebeck Coefficient. Some of the material systems we had to dope the nanolayers by keV implantation of selected species followed by MeV bombardment. In some selected materials systems we formed nanolayered structures by co-deposition followed by MeV bombardment to form Nanocrystals. We will present our finding on the dependence of the thermal conductivity (using 3 omega technique), electrical conductivity (using Van der Pauw method), and the Seebeck coefficient as a function of ion bombardment fluence for several selected materials systems produced in house. Acknowledgement: Research sponsored by the Center for Irradiation of Materials, Alabama A&M University and by the AAMURI Center for Advanced Propulsion Materials under the contract number NNM06AA12A from NASA, and by National Science Foundation under Grant No. EPS-0447675.* Corresponding author: D. ILA; Tel.: 256-372-5866; Fax: 256-372-5868; Email:
[email protected] 11:30 AM - **GG1.4
Direct Write Nanolithography with Focused Mega Electron Volt Protons.
Andrew Bettiol 1 , Jeroen van Kan 1 , Chammika Udalagama 1 , Ee Jin Teo 2 , Mark Breese 1 , Frank Watt 1
1 Department of Physics, National University of Singapore, Singapore Singapore, 2 Department of Materials Science and Engineering, National University of Singapore, Singapore Singapore
Show Abstract12:00 PM - GG1.5
Recent Advances in FIB Technology for Nano-prototyping and Nano-characterisation.
Debbie Stokes 1 , Laurent Rousell 1 , Oliver Wilhelmi 1 , Lucille Giannuzzi 2 , Dominique Hubert 1
1 , FEI Company, Eindhoven Netherlands, 2 , FEI Company, Hillsboro, Oregon, United States
Show AbstractFIB SEM methods are increasingly important for nanoscience and technology applications, as we continue to develop ways to exploit the complex interplay between primary ion and electron beams and the substrate, relationships with gaseous intermediaries. We demonstrate recent progress in FIB SEM processing of conductive and insulating materials for state-of-the-art nanofabrication and prototyping, 3D characterisation and specimen preparation for ultra-high resolution STEM, TEM and nanoanalysis.Progress in FIB milling of soft matter and insulators - There are many potential applications involving soft and/or electrically insulating materials such as polymers, ceramics, glasses and biological specimens. However, we must address the issue of specimen charging, since image drift can have significant consequences on the accuracy and quality of FIB milling, imaging and chemical vapour deposition (CVD). We have developed a method involving a defocused, low energy primary electron beam, correlating ion and electron beam energies and currents with other parameters required for electrically stabilising these challenging materials [1]. Nanofabrication and prototyping - Milling rates and the uniformity of patterns depend on exposure strategy: single-pass or multi-pass execution, definition of leading edges, re-deposition and material-dependent selection of pitch are important aspects for successful prototyping. Erosion of fiducials in overlay exposures, the effects of breaking down individual pattern elements, time considerations and beam blanking are further factors to be taken into account [2]. We show that proper evaluation of the above factors has a dramatic effect on the precision of FIB-patterning and CVD, leading to high-quality fabrication of such structures as Fresnel lenses [2] and photonic arrays [3]. Ultra-high resolution imaging & nanoanalysis - FIB specimen preparation is used to generate ultra-thin lamellae for TEM and STEM. However, FIB milling is often performed using high energy Ga ions (i.e. 30 keV), imparting damage up to ~20 nm at the surface of e.g. silicon. Upper and lower lamellar surfaces carry this damage, easily sufficient to impede high resolution STEM and TEM imaging, and especially problematic for analytical techniques such as EELS. We can reduce surface damage to ~1 nm in silicon using a 2 keV Ga ion beam [4], and with the most up-to-date developments in ion optics, are able to further improve the quality of specimen surfaces.1. Stokes, D., Vystavel, T and Morrissey, F. Journal of Physics D: Applied Physics, 2006. (Submitted).2. Wilhelmi, O., Reyntjens, S., Wall, D., Jiao, C.G., Geurts, R. and Roussel L. Microelectronic Engineering, Proceedings of MNE 2006 (Submitted).3. Morrissey, F., Reyntjens, S, Nakahara, K and Jiao, C. Microsc. Microanal. 2005. 11(Suppl 2)4. Giannuzzi, L.A., Guerts, R. and Ringnalda, J. Microsc. Microanal. 2005. 11(Suppl 2): p. 828-829.
12:15 PM - GG1.6
A High-Throughput Nanofabrication Process Utilizing Ion-Beam Guns for Straightening Multi-Walled Carbon Nanotube Scanning Probes
Sunny Nguyen 2 , Huan Nguyen 1 3 , Ramsey Stevens 4 , Cattien Nguyen 1
2 , Saint Lawrence Academy, Sunnyvalle, California, United States, 1 , ELORET/NASA Ames Research Center, Moffett Field, California, United States, 3 Department Of Chemistry, San Jose State University, San Jose, California, United States, 4 , Modus Technologies, San Francisco, California, United States
Show AbstractThis paper reports the development of ion-beam guns as high-throughput tools for structural straightening of multi-walled carbon nanotubes (MWNTs). This process is important for MWNT scanning probe microscopy in which high performance applications require that the orientation of the MWNT tips be at an angle close to the surface normal. Previously, Focused Ion-Beam (FIB) techniques have been demonstrated for localized modification of carbon nanotube (CNT) structure. Localized structures of a MWNT are rendered to become completely amorphous when utilizing a high ion flux, whereas low ion flux only partially disrupts the crystalline graphitic layers of the MWNT 1. Recently, we have also demonstrated a FIB based fabrication technique for precisely bending a MWNT in 3-dimensional space. The FIB process bends the MWNT at the focal point of the ion beam, and results in the MWNT structure straightening and aligning parallel to the direction of the ion-beam flux2. Herein, we present Scanning Electron Microscopy data demonstrating that MWNT scanning probes with varying initial angles of displacement can be simultaneously straightened to uniform angles with ion-beam guns. Time-dependent studies reveal an optimal ion-beam processing condition for obtaining perfectly straightened MWNT scanning probe tips with angle of displacement normal to a surface. Depending on ion beam processing times, MWNT scanning probe tips with various angles of displacement are achieved. Force spectroscopy data obtained with an atomic force microscope reveals very distinct mechanical behaviors for a set of scanning probes with MWNT tips at different angles of displacement derived from ion-beam processing. As compared to those tips with larger angles of displacement, MWNT tips with the perfect angle normal to the surface exhibit minimal hysteresis in force spectroscopy as a function of distance. High-resolution scanning probe images utilizing ion-beam straightened MWNT probes are also presented. 1.B. W. Wei, J. D’arcy-Gall, P. M. Ajayan, and G. Ramanath, “Tailoring structure and electrical properties of carbon nanotubes using kilo-electron-volt ions,” Appl. Phys. Lett., 83, 3581–3583, 2003.2.R. Stevens, C. Nguyen, and M. Meyyappan, “Nanomanipulation and Fabrication by Ion Beam Molding,” IEEE Trans. Nanotech, 5, 255-257, 2006.
12:30 PM - GG1.7
Spatially Resolved Characterization of Plastic Deformation Induced by Focused-Ion Beam Processing in Structured InGaN/GaN Layers.
R. Barabash 1 , G. Ice 1 , W. Liu 2 , R. Kroeger 3 , H. Lohmeyer 3 , K. Sebald 3 , J. Gutowski 3 , T. Boettcher 3 , D. Hommel 3
1 Materials Science and Technology Div., Oak Ridge National Laboratory, Oak Ridge TN, Tennessee, United States, 2 , Advanced Photon Source, Argonne, Illinois, United States, 3 , Institute of Solid State Physics, Bremen Germany
Show AbstractIn this study the results of polychromatic X-ray microbeam analysis (PXM) of the structural changes caused by FIB in nitride heterostructures are presented and discussed in connection with micro-photoluminescence (µ-PL) and transmission electron microscopy (TEM) data.Using an FEI Nova 200 NanoLab FIB system reference structures have been prepared in samples consisting of InGaN/GaN multi quantum wells grown by metal-organic vapor phase epitaxy on GaN on sapphire templates. Each structure consists of several trenches typically 2 µm wide and 20 µm long with varying distances between the trenches. Trenches were etched down to the sapphire substrate using 30 keV Ga-ions and different ion-beam currents varying from 300 pA to 7 nA. Results from samples with and without a 100 nm SiO2 protection layer are compared. The µ-PL analysis reveals a fatal surface damage on a large scale when working on unprotected samples. For protected samples a decrease in the PL intensity is found only in the immediate vicinity of the trenches. For PXM measurements the microbeam was scanned parallel to the trenches structured in the InGaN/GaN layer with FIB. Laue patterns were recorded at 50 different sample positions. Due to the small size of the microbeam (0.5 µm) it was possible to obtain spatially resolved data from different locations around the trenches. Because the high-energy (8-25 keV) x-ray beam penetrates through the InGaN/GaN and probes the sapphire substrate as well, they both contribute to the observed Laue patterns. The sapphire reflections do not change position with sample translation. They were used as a reference to determine the change in orientation of the InGaN/GaN layer relative to the substrate. The PXM results show that FIB etching distorts the lattice in the InGaN/GaN layer not only in the immediate trench region but in the surrounding area as well. Lattice planes become curved with curvature radius dependent on the distance from the trench, FIB current and the capping layer.The observed lattice distortion is caused by a severe microstructural change which was analyzed using TEM. The TEM analyses in the vicinity of the trenches shows a high density of dislocations and an amophidized layer on top, which could be due to direct surface damage by the FIB beam or redeposition. The research was supported by the U. S. Department of Energy, Division of Materials Sciences and Engineering through a contract with the Oak Ridge National Laboratory. Oak Ridge National Laboratory (ORNL) is operated by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725. Data collection with PXM has been carried out on beamline ID-34-E at the Advanced Photon Source, Argonne IL, and supported by the U.S. DOE under Award No. DEFG02-91ER45439. This work was further supported by the Deutsche Forschungsgemeinschaft under Contracts No. HE 2827/5-1 and HO 1388/25-2.
12:45 PM - G1.8
Electrostatic Focusing for High Energy Ion Nanobeams.
Alexander Dymnikov 1 , Gary Glass 1 , Bibhudutta Rout 1
1 Louisiana Accelerator Center, University of Louisiana at Lafayette, Lafayette, Louisiana, United States
Show AbstractVirtually all high energy focused ion beam (HEFIB) systems presently in use consist of magnetic lenses which have disadvantages when focusing high energy heavy ion beams. One possibility to obtain nominal 20-100 nanometer beam spots with MeV ion beams for nanoscale fabrication, analysis, modification, and irradiation applications is the use of new configurations of electrostatic lenses which have the distinct advantage of having a focusing strength which depends only on the accelerating voltage used to produce the ions, not the charge to mass ratio as with magnetic lenses.For obtaining high energy ion nanobeams certain requirements and restrictions on several parameters must be satisfied, including: ion beam current (or the beam emittance), the total length of the focusing system, the length of lenses, the drift spaces, the object and working distances, the minimum possible size of slits, demagnifications, spherical and chromatic aberrations, and the operating voltages necessary to prevent electrical breakdown. In this paper, the dependence of the beam spot size on several primary system parameters utilizing an electrostatic Russian quadruplet focusing system for 3 MeV ions is presented.
GG2: Pattern Fabrication
Session Chairs
Harry Bernas
Ka-Ngo Leung
Tuesday PM, April 10, 2007
Room 3016 (Moscone West)
2:30 PM - **GG2.1
Solid State Nanopores and their Application to Single Molecule Detection and Characterization.
Jene Golovchenko 1
1 Department of Physics, Harvard University, Cambridge, Massachusetts, United States
Show AbstractRecently individual and isolated solid state pores with nanometer dimensions have been fabricated by a variety of methods in thin insulating membranes. With these nanopores one can electronically detect and characterize individual charged molecules of DNA and other important biological molecules as they translocate in aqueous solution through the nanopore. This talk will review progress in this field and the challenging task of advancing nanopore detectors to the stage where they can be applied to the task of very rapidly sequencing human DNA routinely.
3:00 PM - **GG2.2
Nanospace Reactions Induced by Ion and Electron Beams for Next Generation Lithography
Seiichi Tagawa 1
1 ISIR-Sanken, Osaka University, Ibaraki Japan
Show AbstractThe progress of electronic devices has been supported by advances in lithography, which reached a scale of 90 nm on the mass production stage in 2005. The energy of the exposure source would exceed the ionization potential of the resist materials at the 32 nm scale with the deployment of extreme ultraviolet (EUV) light or an electron beam (EB). Toward 32 nm mass production, fundamental understanding of nanospace reactions in materials is strongly needed. For such purpose, nanospace reactions in resist materials for nanolithography were investigated1. By making clear radiation-induced reactions in resist materials, precise simulation of pattern formation reactions with nanometer accuracy became available2. Correlation between roughness of Nanowires and polymer backbone conformation has been studied by single ion beam.References:1)) T.Kozawa and S.Tagawa, J.Appl.Phys. 99 054509 (2006). 2) A.Saeki, T.Kozawa, S.Tagawa, and H.B.Cao, Nanotechnology 17, 1543 (2006).
3:30 PM - GG2.3
Ion Beam Lithography and Direct Magnetic Patterning of Nanoscale Features with Optimal Definition and Density.
John Baglin 1 , Naoki Kishimoto 2 , Wilhelm Bruenger 3 , Qing Ji 4 , Ka-Ngo Leung 4 , Daryush Ila 5
1 , IBM Almaden Research Center, San Jose, California, United States, 2 , National Institute for Materials Science, Tsukuba Japan, 3 , Fraunhofer Institute ISiT, Itzehoe Germany, 4 , Lawrence Berkeley National Laboratory, Berkeley, California, United States, 5 , Alabama A&M University, Huntsville, Alabama, United States
Show AbstractIon projection technology appears to offer a robust approach for fabricatoin of complex patterns involving multi-scale features patterned at high density, with spatial resolution available at the scale of a few nanometers. Potential applications include future semiconductor chip fabrication, magnetic storage technology, nanoporous membranes, and nanoparticle manipulation. For a specific application, the quality of the ion patterning process depends not only on the ion beam definition, but also on the fidelity with which the pattern image can be registered in the material that is to be patterned. Optimal performance will require the choice of beam and processing conditions to suit the application and the nature, thickness, etc. of the receiving material. Working with primary masks customized with complex multi-dimensional test patterns, we have explored pattern resolution limits at the few-nanometer scale, using ion projection systems to pattern: photoresist or PMMA coatings for lithographic processes; magnetic storage media, templated nanowires, and adsorbate-moderated surfaces. In each case, performance metrics included sharpness of feature definition, absence of granularity within a feature, absence of proximity effects between pattern features, and topographic effects. We shall report on a series of experiments with such systems, in which ion species, energy, and fluence, and also (as appropriate) sample configuration and temperature, were systematically chosen to optimize performance criteria.
3:45 PM - GG2.4
Ion-Beam Assist Nano-Texturing of Templates for Epitaxial Film Growth
Vladimir Matias 1
1 MPA-STC, Los Alamos National Laboratory, Los Alamos, New Mexico, United States
Show AbstractWe present a new paradigm for growth of epitaxial films. Instead of using single crystals, we use ion-beam textured templates with biaxial crystalline orientation as a substrate to grow epitaxial films. The ion-beam assist deposited (IBAD) textured template can be made on arbitrary, but smooth substrates, including flexible metal tapes. With IBAD texturing of MgO we have demonstrated an in-plane mosaic spread FWHM as low as 2° and out-of-plane alignment of less than 1°. Crystalline films grown epitaxially on top of the templates have typically further improved biaxial orientation. For MgO and some other materials with a rock salt crystalline structure, IBAD texturing can be achieved within the first few nanometers of deposited material. This nano-texturing process is very sensitive to the nucleation surface. We review the nano-IBAD textured materials obtained to date.Associated with the IBAD process we have developed an R&D methodology for exploring new epitaxial materials and combinations thereof. The deposition system we use includes reel-to-reel tape transport for a linear transport of substrate materials through the deposition zones. This allows for high-throughput experimentation via a linear combinatorial experimental design. The material we use as a carrier of biaxially oriented templates is a metal tape electropolished to a surface roughness RMS of less than 1 nm on a 5 µm area. This uniform starting material in lengths of tens of meters allows for hundreds of experiments to be performed in one sequence. Other substrates such as ceramics or glass can also be used. A key to high-throughput experimentation is fast in situ characterization. We will present our approach to the in situ experimentation using reflection high-energy electron diffraction and surface ion scattering to characterize the samples. The textured templates we make are used for deposition of functional epitaxial films such as superconductors and semiconductors.This work is supported by the Department of Energy Office of Electricity Delivery & Energy Reliability.
4:30 PM - **GG2.5
Porous Silicon Based Photonics Applications Using Ion Beam Modification.
Ee Jin Teo 1 , Mark Breese 2 , Andrew Anthony Bettiol 2 , Sudesh Wijesinghe 1 , Daniel John Blackwood 1 , Frank Watt 2
1 Materials Science and Engineering, National University of Singapore, Singapore Singapore, 2 Physics, National University of Singapore, Singapore Singapore
Show AbstractThe ability to accurately control the fluence of energetic ion beams has opened up a new way of fabricating light emitting silicon nanocrystals and three-dimensional structures. The ion beam is used to selectively damage the silicon crystal so that the local resistivity of the irradiated region is increased. By controlling the fluence accumulated at each region, we can build up a pattern of localized damage. The rate of porous silicon formation is slowed down during subsequent electrochemical etching in hydrofluoric acid, enabling us to modify the properties of the porous silicon formed in the irradiated region. We demonstrate that the wavelength and intensity of photoluminescence from the porous silicon can be tuned with the fluence of the beam, and a wide range of colour emission from green to red can be produced on a single substrate with sub-micron resolution. By over-etching beyond the end of range of the ion beam, we can produce buried silicon structure surrounded entirely by porous silicon. This offers a novel and direct method of fabricating photonic devices such as silicon waveguides with porous silicon or air cladding, which would be potentially important for optical communications in the mid-IR wavelengths.
5:00 PM - GG2.6
Swift Heavy Ion Beam-Based Nanopatterning Using Self-Assembled Masks.
Jens Jensen 1 , Marek Skupinski 1 , Ruy Sanz 2 , Manuel Hernandez-Velez 3 , Göran Possnert 1 , Klas Hjort 1
1 Department of Engineering Sciences, The Ångström Laboratory, Uppsala University, 751 21 Uppsala Sweden, 2 Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Cientificas, Catoblanco, 28049 Madrid Spain, 3 Departamento de Física Aplicada, Universidad Autónoma de Madrid, 28049 Madrid Spain
Show AbstractFabricating regular nanostructures is of great interest due to their potential applications in data storage, displays, biological sensors and photonic crystals. The most common way of nanopatterning is by irradiation-based lithography. Swift heavy ion irradiation induces localized material transformation in matter, so-called ion tracks. Compared to e.g. e-beam or uv-lithography, ion tracks have the highest contrast between irradiated and non-irradiated regions. In addition, swift heavy ions can transform materials otherwise insensitive to electron or photon irradiation, they can induce very high aspect ratio structures, and the inelastic interaction gives minute scattering. Combining swift heavy ions with high resolution absorbing masks may thus have potential as a lithography technique for nanofabrication. Even if this ‘ion track lithography’ should not immediately give a higher patterning resolution or aspect ratio than other more mature techniques, it enables without further processing direct patterned material modifications. In the high through-put projection lithography the pattern is defined by a mask. To write a pattern onto the mask with nano-sized features e-beam lithography is often used. However, with large high-density nanopatterns the method is very time-consuming, since the pattern is written point by point. In search of high through-put mask patterning an alternative or complementary approach is to use self-assembled materials with nano-scale features.In this work we have used masks of porous anodic alumina membranes (PAM) and of self-assembled colloidal particles, to harness the swift heavy ions and transfer nanopatterns. Results on fabricating regular nanostructures on rutile TiO2 single crystals after MeV ion irradiation through either PAM or self-assembled colloidal masks of silica spheres are presented.TiO2 is an oxide semiconductor with a wide bandgap and a high dielectric constant, both suitable characteristics in electronic and optical applications. In addition, the surface of crystalline TiO2 has interesting properties as a photocatalyst for chemical reactions. By ion track lithography it is possible to prepare well-ordered arrays or patterns of TiO2 with variation in refractive index. Also, as ion tracks in TiO2 have a very high etching selectivity, the induced damage can be developed in HF with very high contrast. Furthermore, nanopatterns with large surface areas useful in photocatalytic work can be fabricated.From an ordered PAM the obtained transferred patterns consisted of pores with the same hexagonal ordering, having a diameter of 70 nm, 100 nm inter-pore distances, and 1100 nm depth. Using self-assembled silica spheres as mask the resulting pattern could be tuned by varying the geometric configuration of the silica sphere layers. Finally, we show direct modifications of the optical properties of TiO2 in a well-defined pattern.
5:15 PM - GG2.7
Ion Beam Patterning of Diblock Copolymer Thin Films
Ho-Cheol Kim 1 , Ranulfo Allen 1 , Joy Cheng 1 , Oun-Ho Park 1 , John Baglin 1
1 , IBM Almaden Research Center, San Jose, California, United States
Show AbstractA diblock copolymer comprises two chemically distinct polymer molecules that are connected together at one end through a covalent bond. In general, most polymers do not mix, due to their very small entropy of mixing and macroscopic phase separation. For diblock copolymers, the connectivity between two polymer molecules limits phase separation to a nanoscopic scale (5 – 50 nm), with complex morphologies being governed by a delicate balance of energy contributions. The relative lengths of the constituent molecules in diblock copolymers determine the shape of the nanoscopic microphase-separated domains (microdomains), which typically range from spheres to cylinders to lamellae. Thin films of block copolymers containing such microdomains have emerged as promising media for the creation of sub-optical lithographic features. In order to pattern surfaces using diblock copolymers, control of orientation of the microdomains is important. Among numerous approaches to control their orientation, formation of thin films of diblock copolymers on energetically neutral surfaces has been most successful and has been studied extensively with diblock copolymers of polystyrene and poly(methyl methacrylate) (PS-b-PMMA). However, one of the challenges remaining for practical patterning is spatially positioning the microdomain patterns on the surface. Previously, macroscopic patterns generated by traditional optical lithography have been used to direct self-assembly of the block copolymers. Optical imaging of thin block copolymer films has also been studied. In this presentation, we report on ion beam patterning of thin diblock copolymer films on amorphous SiO2 substrates. Ion beam exposure introduces local irreversible chemical changes such as crosslinking or chain scission of the polymer constituents. The different response of the polymer constituents to ion irradiation can enable the subsequent selective dissolution of microdomains of one of the constituents using a wet process or thermolysis. We used three different copolymer systems to study fabrication of self-organized patterns within features defined by a patterned ion beam: PS-b-PMMA, a diblock copolymer of polystyrene and poly(ethylene oxide) (PS-b-PEO), and a PS-b-PEO and organosilicate hybrid. By this approach, patterns of nanoscopic features (e.g. of ~ 20nm pores in a 30nm thick film of PS-b-PMMA), reflecting microdomains of oriented block copolymers, have been created, within larger geometrical areas defined by a patterned ion beam. Details on the effects of ion species, energy, and radiation dose on the patterning process will be addressed in this presentation.
5:30 PM - GG2.8
MeV Heavy Ion Lithography in Silicon.
Gary Glass 1 , Bibhudutta Rout 1 , Alexander Dymnikov 1 , Yongqiang Wang 2 , Richard Greco 2
1 Louisiana Accelerator Center, University of Louisiana at Lafayette, Lafayette, Louisiana, United States, 2 Ion Beam Materials Laboratory, Los Alamos National Laboratory, Los Alamos, New Mexico, United States
Show AbstractThe use of MeV heavy ions for masked or direct write lithography applications in semiconductors has been restricted, in part, by the inability to adequately reduce the beam spot dimensions using focusing systems utilizing magnetic quadrupole lenses. However, the introduction of new electrostatic focusing systems for MeV heavy ions will enable direct writing of nanoscale patterns in silicon and other substrates using a process defined as heavy ion beam (HI-beam) writing coupled with wet etch processing. This electrostatic lens-based technique will also allow the implanting of very thin (<500 nm) layers in sub-100 nm sized areas with selected heavy ions to change electrical/magnetic/chemical/optical properties of these areas in a controlled fashion. In this presentation, the use of MeV ions coupled with wet etching to create microstructures Si(100), Si(110) and Si(111) is demonstrated and thus, these experiments establish the feasibility of utilizing focused high energy (MeV) heavy ions for deep micromachining in Si. The microscale structures in resists were patterned by P-beam writing at our laboratory, irradiated with several heavy ions at different energies and fluences, and chemically wet etched to produce 3-dimensional structures. The effectiveness of the irradiation and etching processes for fabrication and the application of HI-beam direct writing is discussed.
5:45 PM - GG2.9
High-aspect-ratio Micromachining of Fluoropolymers using Focused Ion Beam.
Yoshinori Matsui 1 , Nozomi Miyoshi 2 , Akihiro Oshima 2 , Shu Seki 1 , Masakazu Washio 2 , Seiichi Tagawa 1
1 The Institute of Scientific and Industrial Research, Osaka Univ., Osaka Japan, 2 Advanced Research Institute for Science and Engineering, Waseda Univ., Tokyo Japan
Show AbstractGG3: Poster Session: Patterning, Ripples and Self Assembly
Session Chairs
John Baglin
Paul Chu
Daryush Ila
Naoki Kishimoto
Wednesday AM, April 11, 2007
Salon Level (Marriott)
9:00 PM - GG3.3
Scaling Studies of Nanoscale Patterns on InP(111) Surfaces after MeVImplantation
Shikha Varma 1 , Dipak Paramanik 1
1 , Institute of Physics, Bhubaneswar, Orissa, India
Show Abstract9:00 PM - GG3.4
Performance of Programmable Proximity Aperture MeV Ion Beam Lithography System.
Sergey Gorelick 1 , Nitipon Puttaraksa 2 1 , Timo Sajavaara 1 , Mikko Laitinen 1 , Tommi Ylimaki 1 , Ananda Sagari 1 , Harry Whitlow 1
1 Physics, University of Jyväskylä, Jyväskylä Finland, 2 Physics, Chiang Mai University, Chiang Mai Thailand
Show Abstract9:00 PM - GG3.5
Synthesis of High-k Polycrystalline Nano-array Induced by Electron Beam Irradiation
Huang Anping 1 , Liu Xuanyong 1 , Chu Paul K. 1
1 , City university of HK, HongKong Hong Kong
Show Abstract9:00 PM - GG3.6
MeV Ion Beam Fabrication of Nanopore.
Renato Minamisawa 1 , Robert Zimmerman 1 , Claudiu Muntele 1 , Daryush Ila 1
1 Center for Irradiation of Materials, Alabama A&M University, Huntsville, Alabama, United States
Show AbstractWe have used MeV ion beams to fabricate nanopores in various fluoropolymer membranes. We have developed an in house system to produce nanopores. Using MeV ion beams we developed a method to produce pores from a few nanometers to one micron diameter. A thin film of each polymer was mounted to cover a window to a gas filled chamber and then exposed to a uniformly scanned MeV ion beam masked to define the exposed area. The gas leak rate through the fabricated pores was monitored by an in situ RGA system both during and after each bombardment to correlate the leakage with the total area of the pores produced. In this project we used MeV light and MeV heavy ions to best define the pore diameter through each hole and the pore entrance and exit dimensions in the membranes. We will present our results during the meeting. Acknowledgement: Research sponsored by the Center for Irradiation of Materials, Alabama A&M University and by National Science Foundation under Grant No. EPS-0447675.
9:00 PM - GG3.8
The Role of the Ar+ Irradiation Dose on Amorphous-crystalline Ripple Formation in Si.
Souren Grigorian 1 , Joerg Grenzer 2 , Semen Gorfman 1 , Andreas Biermanns 1 , Ullrich Pietsch 1
1 , University of Siegen, Siegen Germany, 2 , Institute of Ion Beam Physics and Materials Research, Dresden Germany
Show Abstract9:00 PM - GG3.9
Exchage Bias Field Change in Ferromagnet/Antiferromagnet Bilayer Thin Films by He Ion Irradiation using DuoPIGatron.
Yongoh Noh 1 , Cheolgi Kim 1 , Chongoh Kim 1
1 , Chungnam National Univ., Taejeon Korea (the Republic of)
Show Abstract9:00 PM - GG3: PRamp;SA (P)
GG3.7 TRANSFERRED TO GG4.5
Show Abstract
Symposium Organizers
Daryush Ila Alabama A&M University
John Baglin IBM Almaden Research Center
Naoki Kishimoto National Institute for Materials Science
Paul K. Chu City University of Hong Kong
GG4: Ripples and Self Assembly
Session Chairs
Daryush Ila
Ahmet Oztarhan
Wednesday AM, April 11, 2007
Room 3016 (Moscone West)
9:30 AM - **GG4.1
Surface Morphology Evolution in Sputter Erosion
Michael Aziz 1
1 Div. Engrg. & Appl. Sci., Harvard University, Cambridge, Massachusetts, United States
Show AbstractFocused and unfocused ion beam irradiation of a solid changes the surface morphology by sputter erosion and material relaxation processes. Their interplay can result in completely smooth surfaces; self-organized nanoscale corrugation, dot, or hole patterns; or self-sharpening high-sloped shock fronts that propagate instead of dissipating. Current understanding of these phenomena will be reviewed from an experimental and a theoretical perspective.
10:00 AM - GG4.2
Nano-ripple Structure Formation on Silicon Surface by Gas Cluster Ion Beam Fabrication and its Applications to III-Nitride Nanorods Fabrication.
O. Lozano 1 2 , H. Seo 3 , X. Wang 1 2 , J. Liu 1 2 , Q. Chen 1 2 5 , L. Tu 4 5 , Y. Lin 4 5 , Y. Cheng 4 5 , I. Chen 6 , K. Lee 6 , H. Tung 6 , T. Kao 6 , Wei-Kan Chu 1 2 , P. Chinta 1 2 , P. Wadekar 1 2
1 Department of Physics, University of Houston, Houston, Texas, United States, 2 Texas Center for Superconductivity, University of Houston, Houston, Texas, United States, 3 Department of Physics, University of Arkansas, Little Rock, Arkansas, United States, 5 Center for Nanoscience and Nanotechnology, National Sun Yat-Sen University, Kaohsiung, Taiwan, Taiwan, 4 Department of Physics, National Sun Yat-Sen University, Kaohsiung, Taiwan, Taiwan, 6 Department of Materials Science and Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan, Taiwan
Show AbstractGas cluster ion beam (GCIB) have been used to fabricate nano-ripple structures on Si substrates. In this work, using (Ar)n+ clusters at 30 kV acceleration, where n~3,000, we have observed nano-ripple formations on the silicon surface after GCIB bombardment. The wavelength, amplitude and the dimensions of the ripples were studied in an effort to characterize the morphology as a function of cluster beam’s angle of incidence, crystallographic orientations of the substrate, and the ion dosages. The underlying physics of ripple formation will be conjectured and the applications of nanostructures fabrication on rippled (111)-Si substrates in producing nanorods of III-nitrides, such as GaN, InGaN, and InAlN, will be presented.
10:15 AM - GG4.3
Effects of Ion Beam Irradiation on Formation of InAs Quantum Dots.
Hugh McKay 1 , Jennifer Lee 1 , Aaron Dehne 1 , Joanna Mirecki-Millunchick 1
1 Dept. of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan, United States
Show AbstractIn this work, the influence of Ga+ ion dose on InAs quantum dot (QD) formation was studied using a novel grow-pattern-characterize system. An ultra high vacuum (UHV) focused ion beam (FIB) column, which is integrated to a molecular beam epitaxy growth system, was used to pattern GaAs buffer layers grown on GaAs(001) substrates. Patterns consisted of arrays of 5 μm squares with ion doses N ranging from 5×1012 < N < 5×1016 ions/cm2. After patterning, samples were transferred to the growth chamber in vacuo, and two monolayers of either InAs or GaAs were deposited at a substrate temperature of 500 °C while the surface was monitored by reflection high energy electron diffraction (RHEED). For InAs growth, RHEED patterns became spotty indicating growth of 3D InAs islands. After removal from the UHV system samples were examined via tapping mode atomic force microscopy (AFM) which showed the influence of ion dose on InAs QD density. We found that below a threshold dose of N≈ 1014 ions/cm2 there was little enhancement of QD density on the patterned regions. Ex situ AFM did reveal surface swelling in those regions, possibly due to damage enhanced oxidation or amorphization of the substrate. For doses above the threshold, increased QD densities could be observed for increased ion doses. For growth temperatures above the indium desorption temperature on GaAs, the initially spotty RHEED patterns became streaky a few minutes after growth. AFM on these samples showed QDs occurring only on the patterned regions of the sample. GaAs growth upon patterned substrates, on the other hand, did not result in the formation of any 3D structures, indicating that the features observed on InAs patterned samples are the result of enhanced nucleation rather than artifacts of the ion beam exposure.
10:30 AM - GG4.4
Time evolution of Nano Dots created on InP(111) surfaces by keV irradiation
Dipak Paramanik 1 , Subrata Majumdar 1 , Smruti Sahoo 1 , Shikha Varma 1
1 XPS/SPM laboratory, Institute of physics, Bhubaneswar, Orissa, India
Show AbstractFabrication of Nanodots on semiconductor surfaces has immense importance due to their application in memory and optoelectronic devices. Ion irradiation methods display an easy and cost effective route for developing self assembled nano structures. We have studied the formation of nano dots on InP(111) surfaces by 3keV Ar ion irradiation. The distribution of nano dots on InP surfaces has been investigated by Scanning Probe Microscopy. At 5 minute irradiation of InP surface with Ar ions leads to the appearance of dots on the surface. The density of dots is, however very small. These dots have been obtained at room temperature, in the absence of sample rotation, with an angle of 15 degree between the ion axis and the sample normal. After an irradiation of 10 min a large density of dots appear on InP surface and display a narrow distribution of size and height. The dots at this stage have an average diameter of 25nm and a height of 4nm. With increased irradiation time the average size and the height of the dots increase and their distribution also become broader. This scenario, however, changes after a 40min irradiation where large hexagonal shaped dots of about 100 nm diameter and 40 nm height are observed. Surprisingly, for larger irradiation times a reduction in the size and heights is observed. The studies suggest “Critical Time” , such that the dot structures grow with time below critical time but diminish in size beyond it. We will show that the Bradley Harper Theory is not sufficient to explain the critical time behavior and the non-linear effects of Kuramoto Sivashinsky formalism are necessary. Furthermore the growth exponent in the present study has been calculated to be 0.85 for the regime where non-linear effects are not important. Once the non-linear effects become important, the growth exponent of 0.31 is obtained. Height-height correlation studies provide a roughness exponent of 0.77. Power spectral density results indicate diffusion to be a possible smoothening mechanism on these surfaces. X-ray photoemission Spectroscopy (XPS) on the ion-irradiated surfaces indicate a preferential sputtering of Phosphorus from InP surfaces during irradiation. Raman Spectroscopy shows that ion-irradiated surface is under slight compressive stress, which becomes maximum at the “critical time”. Furthermore very small dots appear on the surface only when the stress is negligible.
10:45 AM - GG4.5
Atomistic Origins of Surface Evolution and Electronic Structure Modification due to Ion Bombardment.
Nagarajan Kalyanasundaram 1 , Harley Johnson 1 , Jonathan Freund 1 2
1 Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States, 2 Aerospace Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States
Show AbstractGG5: Surface Modification and Patterning
Session Chairs
Satilmis Budak
Naoki Kishimoto
Wednesday PM, April 11, 2007
Room 3016 (Moscone West)
11:30 AM - **GG5.1
Patterned Adhesion of Cells
Robert Zimmerman 1
1 Center for Irradiation of Materials, Alabama A&M University, Normal, Alabama, United States
Show AbstractThe strength, durability and low density make Glassy Polymeric Carbon (GPC) a favored material for in vivo medical applications, including transcoetaneous electrodes and replacement heart valves. Natural tissue heals completely, even in direct contact with a GPC implant, normally a desirable consequence of the exceptional biocompatibility of pure carbon. However, the possible release of endothelial tissue that forms on the smooth surfaces of the GPC heart valve has the potential of creating an embolism. We have used oxygen ion bombardment to increase the nanoscale surface roughness, to enhance cell adhesion, and we have used implanted silver ions near the surface of GPC to completely inhibit cell attachment and adhesion. Either technique may be used to improve the safety and function of an implant, the latter being appropriate for the surfaces of the GPC heart valve exposed to the blood stream. Cells attach and strongly adhere to areas close to the silver implanted surfaces. Patterned ion implantation permits precise control of tissue growth on GPC and other biocompatible substrates. Cell growth limited to micrometric patterns on a substrate may be useful for in vitro studies of associated biological processes in an otherwise identical environment. The patterned inhibition of cell attachment persists for periods of time significant relative to typical implant lifetimes.
[email protected] sponsored by the Center for Irradiation of Materials, Alabama A&M University and by National Science Foundation under Grant No. EPS-0447675.
12:00 PM - **GG5.2
Nano-film and Coating for Biomedical Application Prepared by Plasma-based Technologies.
Xuanyong Liu 1 2 , Paul Chu 2 , Chuanxian Ding 1
1 , Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai China, 2 Department of Physics & Materials Science, City University of Hong Kong, Hong Kong China
Show Abstract12:30 PM - **GG5.3
Modification of Surface Morphology of UHMWPE for Biomedical Implants.
Ahmet Oztarhan 1 , N. Kaya 1 , A. Ozdesir 2 , E. Urkac 3 , S. Budak 4 , C. Muntele 4 , B. Chhay 4 , E. Oks 5 , A. Nikolaev 5 , D. Ila 4
1 Bioengineering, Ege University , Izmir Turkey, 2 Research and Development, Petkim, Izmir Turkey, 3 Material Science, Izmir Yuksek Teknoloji Enstitusu, Izmir Turkey, 4 Ctr. For Irradiation of Materials, Alabama A&M University, Normal, Alabama, United States, 5 , High Current Electronics Institute, Tomsk Russian Federation
Show AbstractAn attempt was made to change the surface morphology of UHMWPE samples at nano scale by Ti+O hybrid ion implantation to produce surface nanostructured polymer-titanium oxide composites, where wear resistance, UV protection, increased hardness, chalking stability and biocompatibility are desired. UHMWPE samples were Ti+O hybrid ion implanted (simultaneously) by using improved MEVVA ion implantation technique with an extraction voltage of 30 kV and fluence of 10E17 ions/cm2.Characterizations of the implanted samples with ATR - FTIR, RBS and UV-Vis - NIR spectrum were compared with the un-implanted ones. Implanted and un-implanted samples were also thermally characterized by TGA and DSC. Optical absorption of the samples has also been measured. C–H bond concentration decreased and UV absorption (UV protection) increased by Ti+O hybrid ion implantation. The results indicated that the linear chain structure of UHMWPE are damaged and crosslink number was increased compared to unimplanted ones. More results will be presented and discussed together with potential applications such as functional paints, nano composite biomedical materials and protection of historic structures and archaeological assets.
GG6: Nanoparticles, Nanocrystals and Defects
Session Chairs
Wednesday PM, April 11, 2007
Room 3016 (Moscone West)
2:30 PM - **GG6.1
Ion Beam-induced Quantum Dot Synthesis in Glass.
Harry Bernas 1 , Roch Espiau de Lamaestre 1 2 3
1 , CSNSM-CNRS, Université Paris Sud, 91405-Orsay France, 2 , Fontainebleau Research Center, Corning SA, 77210 Avon France, 3 , CEA-Grenoble, SPSMS/LCP, 38054-Grenoble cedex 9 France
Show Abstract3:00 PM - GG6.2
Ion Beam Synthesis and Properties of Magnetic Quantum Dots Embedded in SiO2 Thin Films
Ying Kit Yuen 1 , Quan Li 1 3 , Ning Ke 1 , Wing Yiu Cheung 1 , Quan Li 2 3 , Joerg Lindner 4
1 Dept of Electronic Engineering, Chinese University of Hong Kong, Shatin Hong Kong, 3 Materials Science & Technology Research Centre, Chinese University of Hong Kong, Shatin Hong Kong, 2 Dept of Physics, Chinese University of Hong Kong, Shatin Hong Kong, 4 Institut fur Physik, University of Augsburg, Augsburg Germany
Show Abstract3:15 PM - GG6.3
Converting Polycrystals into Single Crystals – Selective Grain Growth by High Energy Ion Bombardment.
Sven Olliges 1 , Patric Gruber 2 , Anita Bardill 1 , Daniel Ehrler 1 , Heinz Carstanjen 2 , Ralph Spolenak 1
1 Department of Materials, ETH Zurich, Zurich Switzerland, 2 , Max Planck Institute for Metals Research, Stuttgart Germany
Show Abstract3:30 PM - GG6.4
Controlled Growth of Conducting Carbon Nanowires by Ion Irradiation: Electrical and Field Emission properties
Amit Kumar 1 , L. Filip 2 , J. Carey 2 , J. Pivin 3 , A. Tripathi 1 , D. Avasthi 1
1 Materials Science Deivision, IUAC, New Delhi India, 2 Nano-Electronics Centre, Advanced Technology Institute, School of Electronics and Physical Sciences, University of Surrey, Guildford United Kingdom, 3 CSNSM, Orsay Campus, Orsay France
Show AbstractThe controlled growth of a single nanowire or an ensemble of nanowires, their growth direction, suitable alignment and spacing on a substrate is of importance for the applications. The simplification of the nanowire fabrication procedure as well as the development of large scale and low price production methods remains open problems. In the present work, we have demonstrated simple technique for fabrication of conducting carbon nanowires in fulllerene thin films by ion beams. We report the control growth of carbon nanowires, their structural, electrical and field emission properties. All the nanowires are perfectly parallel to each other, and are perpendicular to the substrate. The density (spacing), growth direction and length of these carbon nanowires simply can be changed by ion fluence, angle of irradiation and the film thickness, respectively. Conductive atomic force microscopy shows that the nanowires are 20 to 60 nm in radius and have semiconducting properties up to a certain fluence. The field emission measurements on these nanowires reveal that the threshold voltage is about ( ~9 V/micro m.), whereas the as deposited fullerene films shows a break down at ( ~ 51 V/micro m.). The present approach of making controlled conducting carbon nanowires is quite promising, as it takes few seconds of ion irradiation and no catalyst require. The possibility's of the application of these nanowires is demonstrated as electron filed emitters.
3:45 PM - GG6.5
GaN Nanorod Arrays on Si Self-implanted (111) Si-Substrates.
H. Seo 1 2 3 , N. Badi 1 2 , Q. Chen 1 2 5 , L. Tu 4 5 , Y. Lin 4 5 , Y. Cheng 4 5 , X. Wang 1 2 , J. Liu 1 2 , O. Lozano 1 2 , Wei-Kan Chu 1 2
1 Physics, University of Houston, Houston, Texas, United States, 2 Texas Center for Superconductivity, University of Houston, Houston, Texas, United States, 3 Department of Physics, University of Arkansas, Little Rock, Arkansas, United States, 5 Center for Nanoscience and Nanotechnology, National Sun Yat-Sen University, Kaohsiung, Taiwan, Taiwan, 4 Department of Physics , National Sun Yat-Sen University, Kaohsiung, Taiwan, Taiwan
Show AbstractWe have successfully fabricated the array pattern of epitaxial GaN nanorods by self-implantation on Si substrates. The ion bombardments prior to deposition induce changes of surface morphology of Si substrate and thus, in the film growth, results in the formation of capillary tubes, which are the valleys surrounded by islands. This is attributed to the nanocapillary condensation of Ga droplets that serve as a medium to the vapor-liquid-solid growth of nanorods out of its supporting matrix. The morphology of substrate is closely related to the parameters during the implantation process which determine the size and density of nanorods.
4:30 PM - GG6.6
Nanofabrication Based on Ion Beam-Laser Interactions with Self-Assembly of Nanoparticles.
Naoki Kishimoto 1 , Kenji Saito 2 1 , Naoki Umeda 1 , Jin Pan 2 1 , Yoshihiko Takeda 1
1 Quantum Beam Center, National Insitute for Materials Science, Tsukuba, Ibaraki, Japan, 2 Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
Show AbstractMetal-nanoparticle patterning is important for plasmonic applications, such as ultrafast nonlinear devices and single electron transistors, etc. Ion beam-based techniques offer various possibilities for robust spatial control of nanoparticles. Since ion implantation is inherently good at depth control of solutes or nanoparticles, additional lateral control may result in 3D control of nanoparticles. There are two approaches to the lateral control: one is patterning ion/atom supply (masked implantation, FIB, IPL, etc.) and the other is patterning interactive fields with solutes/precipitates (electro-magnetic fields, mechanical fields, etc.). To control nanoparticle assemblies, self-assembling mechanisms have to also be used, more or less. In this paper, we explore to control nanoparticle assemblies by controlling energy fields with laser irradiation under ion implantation. Laser lights were irradiated into SiO2, either sequentially or simultaneously with ion implantation. Ions of 60 keV Cu- or 3 MeV Cu2+ and photons of 532 nm or 355 nm were used to study effects on nanoparticle evolution. Sequential laser irradiation of 532 nm tends to cause a decay of surface plasmon resonance (SPR), i.e., dissolution of Cu nanoparticles, though 355 nm-laser causes some enhancement of SPR. The 532 nm-laser directly excites SPR of pre-existent nanoparticles and acts as the nanoparticle eraser. Contrarily, simultaneous laser irradiation under ion implantation gives a favorable condition to enhance SPR, i.e., nanoparticle precipitation. The energy fields of laser interactive with nanoparticle evolution can be used for controlling nanoparticle assembly.
4:45 PM - GG6.7
Ion Beam Irradiation of Embedded Nanoparticles: Towards an in-situ Control of Size and Spatial Distribution
Giancarlo Rizza 1 , Yaasiin Ramjauny 1 , Thierry Gacoin 2 , Sylvain Henry 3
1 Laboratoire des Solides Irradiés, CEA/Ecole Polytechnique , Palaiseau France, 2 Groupe de Chimie du Solide, Laboratoire de Physique de la Matière Condensée, UMR CNRS 7643, Ecole Polytechnique , Palaiseau France, 3 Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse, CNRS-IN2P3 , Orsay campus France
Show AbstractIon beam synthesis (IBS) has been extensively employed in the close past to fabricate a precipitate second phase with controlled properties in term of chemical composition, size and spatial distribution. The research activity in this field is stimulated by the possibility to produce high volume fraction of nanometer size particles (NCs) with specific properties and potential applications in nanoelectronics and nanophotonics. Metallic NCs embedded in a dielectric matrix are particularly interesting because of their non linear optical properties with high potential for application in optoelectronic field. Moreover, the surface plasmon resonance depends on the NCs size and shape as well as their chemical environment. Although ion-implantation and ion-mixing proved to be suitable in obtaining NCs based materials, the uncontrolled nucleation and growth processes results in a broad spatial and size distribution of NCs and reduces the possible practical applications.On the other hand, the energy released by charged accelerated particles can be used to tailor the properties of already formed NCs, embedded or deposited on a surface. This new applied direction is referred to the ion beam processing (IBP).The purpose of the present work is twofold : on one hand, by combining the chemical synthesis of Au NCs embedded in a silica matrix with the ion irradiation we give a guideline method for overcoming the difficulty of controlling the NCs size and spatial distribution associated with ion implantation technique [1]. Moreover, we show that the complete dissolution of large Au NCs (15-20 nm) induced by the irradiation (Au 4MeV) results in the formation of a nearly monodisperse size distribution (0.4 nm) of small precipitates with a mean size of 2 nm.On the other hand, we have started a systematic investigation on the basic mechanisms of NCs stability under irradiation. The irradiation, inducing the dissolution of the embedded Au NCs, promotes the formation of a halo of satellites around them. We show that the growth kinetics of the satellites can be described by a two steps process. Besides, describing the satellites evolution under continuous monomer supply we were able to give an insight into the basic mechanisms of the precipitation under irradiation. In particular, we use our experimental results to critically analyze the recently proposed [2], and still controversial, inverse Ostwald ripening mechanism.[1] G.Rizza, H. Cheverry, T. Gacoin, A. Lamasson, S. Henry, Journal of Applied Physics (2006) in press[2] K.H.Heinig, T. Müller, M.Strobel, B.Schmidt, W.Möller, Appl. Phys. A 77 (2003) 17
5:00 PM - GG6.8
Self-assembled Nanostructures by Focused Ion Beam Nanofabrication.
Jie Lian 1 , Qiangmin Wei 1 , Lumin Wang 1 , Rodney Ewing 1
1 , Univ. of Michigan, Ann Arbor, Michigan, United States
Show Abstract5:15 PM - GG6.9
Core-Satellite Metallic Nanoclusters in Silica Obtained by Multiple Ion Beam Processing
Giovanni Mattei 1 , Valentina Bello 1 , Paolo Mazzoldi 1 , Giovanni Pellegrini 1 , Chiara Maurizio 2 , Giancarlo Battaglin 3
1 Department of Physics, University of Padova, Padova Italy, 2 , CNR-INFM, ESRF, GILDA-CRG, Grenoble France, 3 Department of Chemical Physics, University of Venice, Venice Italy
Show AbstractComposite materials made by monoelemental or metal alloy nanoclusters embedded in silica-based matrices exhibit peculiar nonlinear optical properties which are function of the cluster size and composition. Sequential ion implantation in glass has demonstrated to be a very effective technique to obtain such nanocomposites. In this work, we use an ion beam-based multi-step approach for synthesizing embedded nanoclusters and for modifying in particular their near-field and far-field properties, through an ion-beam controlled tuning of the dielectric environment around them. In the first step noble metal nanoclusters are synthesized in silica by ion implantation in combination with thermal treatments. The second step is ion irradiation which allows, by properly adjusting the nuclear component of the energy released to the system, to create a peculiar nanostructure made of a halo of small satellite nanoclusters around the original ones. For instance, in the Au-Ag system, irradiation with He+, Ne+, Ar+ or Kr+ ions promotes a preferential extraction of Au from the alloy, resulting in the formation of Au-enriched "satellite" nanoparticles around the original AuxAg1-x cluster. A systematic investigation of the role played by the irradiation parameters (i.e., fluence, flux, energy of the implanted ions) on controlling the satellite nanostructure has been carried out. A correlation between the nuclear component of the energy released by the irradiating ions and the size and density of the satellite clusters is found. We have used this ion beam based technique to promote for instance a red-shift the plasma resonance absorption of the metallic clusters exploiting the coupling of the satellite nanoclusters with the original clusters. Due to the remarkable enhancement of the local fields (that we have simulated within a Generalized Multiparticle Mie approach), the obtained nanocomposite glass can be very promising for applications in nonlinear optics.
5:30 PM - GG6.10
Formation of Silver Nanoparticles in Silicon by Metal Vapor Vacuum Arc Ion Implantation.
Q. Chen 1 2 5 , H. Seo 3 , I. Rusakova 1 2 , L. Tu 4 5 , Y. Cheng 4 5 , H. Zhang 6 , Z. Zhang 1 2 , X. Wang 1 2 , J. Liu 1 2 , O. Lozano 1 2 , Wei-Kan Chu 1 2
1 Department of Physics, University of Houston, Houston, Texas, United States, 2 Texas Center for Superconductivity, University of Houston, Houston, Texas, United States, 5 Center for Nanoscience and Nanotechnology, National Sun Yat-Sen University, Kaohsiung, Taiwan, Taiwan, 3 Department of Physics, University of Arkansas, Little Rock, Arkansas, United States, 4 Department of Physics , National Sun Yat-Sen University, Kaohsiung, Taiwan, Taiwan, 6 Institute of Low Energy Nuclear Physics, Beijing Normal University, Beijing, Beijing, China
Show Abstract5:45 PM - GG6.11
Pulsed Low-energy Ion-beam Induced Nucleation and Growth of Ge Nanocrystals on SiO2.
Anatoly Dvurechenskii 1 , Nataliya Stepina 1 , Pavel Novikov 1 , Victor Kirienko 1 , Vladislav Armbrister 1 , Anton Gutakovskii 1 , Valery Kesler 1 , Rainer Groetzschel 2
1 Siberian Branch of Russian Academy of Science, Institute of Semiconductor Physics, Novosibirsk Russian Federation, 2 , Research Center Rossendorf, Dresden Germany
Show AbstractGG7: Poster Session: Nanostructures, Surfaces and Applications
Session Chairs
John Baglin
Paul Chu
Daryush Ila
Naoki Kishimoto
Thursday AM, April 12, 2007
Salon Level (Marriott)
9:00 PM - GG7.1
Perfect Ordering in Thin, Porous Alumina Template Films on Supporting Substrates by Focussed Ion Beam Pre-patterning
Adam Robinson 1 , Gavin Burnell 2 , Judith MacManus-Driscoll 1
1 Department of Materials Science and Metallurgy, University of Cambridge, Cambridge United Kingdom, 2 School of Physics and Astronomy, University of Leeds, Leeds United Kingdom
Show AbstractAnodic aluminium oxide (AAO) templates form an ideal route to the production of arrays of nanostructures; they are robust, withstand high temperatures and can be produced with a range of geometries, enabling fabrication of arrays of nanoparticles and wires by a range of techniques. However, the majority of the work on AAO templates has focused on thick foils, which prohibits the fabrication of devices from the nanostructured materials deposited in the pores. Here we present work on the production of thin (<1 μm), perfectly ordered AAO templates on supporting silicon substrates by focussed ion beam (FIB) pre-patterning, followed by anodisation. Both hexagonal and square ordered arrays of cylindrical pores were produced over a 15x15 μm area. The pitch and pore sizes were controlled between 100 and 200 nm (pitch) and 50 and 70 nm (pore size). We also report on pattern transfer into the supporting substrate by argon ion milling.
9:00 PM - GG7.10
In Vitro Apatite Formation on Polymer Substrates Irradiated by the Simultaneous Use of Oxygen Cluster and Monomer Ion Beams
Masakazu Kawashita 1 , Rei Araki 1 , Gikan Takaoka 1
1 Ion Beam Engineering Experimental Laboratory, Kyoto University, Kyoto Japan
Show AbstractBioactive and flexible materials with low elastic moduli could be obtained, if organic fibres were fabricated into two-dimensional structures and their surfaces was modified with a functional groups effective for apatite nucleation. They are expected to be useful as ligament substitutes. Cluster ion beams have unique irradiation effects such as high-energy-density deposition, low-damage irradiation etc. In this study, polyethylene (PE) substrates as one example of polymers were irradiated at 1015 ions/cm2 by the simultaneous use of oxygen (O2) cluster and monomer ion beams. The acceleration voltage for the ion beams was changed from 3 to 9 kV. Apatite-forming ability of the substrates was examined by soaking them into a metastable calcium phosphate solution that had 1.5 times the ion concentrations of a normal simulated body fluid (1.5SBF) at 36.5°C for 7 days. Some substrates were soaked in 1M-CaCl2 solution for 1 day after the irradiation. The hydrophilic functional groups such as COOH and C-OH groups were formed at the PE surfaces by the irradiation. It is considered that the chemical bonds of PE were partially broken by O2 monomer ions to form dangling bonds and, at the same time, a large number of oxygen atoms were supplied to the dangling bonds by O2 cluster ions to form hydrophilic groups. The amount of the functional groups increased with increasing acceleration voltage, but the hydrophilicity of the substrates decreased slightly at 9 kV. This might be attributed to the carbonization of the PE substrate caused by the irradiation at high acceleration voltage of 9 kV. The irradiated PE substrates formed apatite in 1.5SBF, whereas unirradiated ones did not form it. This indicates that the functional groups such as COOH groups, which were formed at the PE surface by the irradiation, induced apatite nucleation in 1.5SBF. The apatite-forming ability increased with increasing acceleration voltage up to 6 kV, but slightly decreased at 9 kV. The decrease in the apatite-forming ability at 9 kV also might be attributed to the carbonization. The apatite formation was remarkably promoted by the subsequent CaCl2 solution treatment. This is explained as follows. When the substrate is soaked in 1.5SBF, the calcium ions retained at the PE surface by the CaCl2 solution treatment are released into 1.5SBF to increase the ionic activity product of the surrounding fluid with respect to apatite. In conclusion, it is believed that a cluster ion beam irradiation can be a promising technique for giving an apatite-forming ability on a polymer surface.
9:00 PM - GG7.11
Growth of Stabilizer Free Zirconium Oxide Coatings by Ion Beam Assisted Deposition.
Chin Li Cheung 1 , Gonghua Wang 1 , Shailaja Varma 2 , Hani Haider 2 , Kevin Garvin 2 , Fereydoon Namavar 2
1 Chemistry, University of Nebraska - Lincoln, Lincoln, Nebraska, United States, 2 Orthopaedic Surgery and Rehabilitation, University of Nebraska Medical Center, Omaha, Nebraska, United States
Show Abstract9:00 PM - GG7.12
Thermal Characterization of W+C Ion Implantation based Nanofabricated UltraHigh Molecular Weight Polyethylene (UHMWPE) Samples
E. Urkac 1 , Ahmet Oztarhan 2 , F. Tihminlioglu 1 , N. Kaya 2 , S. Budak 3 , C. Muntele 3 , E. Oks 4 , A. Nikolaev 4 , D. Ila 3
1 Department of Materials Science, IYTE, Urla Turkey, 2 Department of Bioengineering, Ege University, Bornova/ Izmir Turkey, 3 Center for Irradiation of Materials, Alabama A.&M. University, NORMAL, Alabama, United States, 4 , High Current Electronics Institute, Tomsk Russian Federation
Show Abstract9:00 PM - GG7.13
Surface Characterization of Ti + C ion implantation based Nanofabricated UHMWPE samples
N. Kaya 2 , Ahmet Oztarhan 2 , E. Urkac 3 , S. Budak 1 , C. Muntele 1 , E. Oks 4 , A. Nikolaev 4 , D. Ila 1
2 Department of Bioengineering, Ege University, Bornova/ Izmir Turkey, 3 Department of Materials Science, IYTE, Urla, Izmir Turkey, 1 Center for Irradiation of Materials, Alabama A.&M. University, NORMAL, Alabama, United States, 4 , High Current Electronics Institute, Tomsk Russian Federation
Show Abstract9:00 PM - GG7.14
RGA and thermal analysis of Ti+C hybrid ion implantation based Nanofabricated UHMWPE samples
N. Kaya 1 , Ahmet Oztarhan 1 , E. Urkac 2 , S. Budak 3 , C. Muntele 3 , E. Oks 4 , A. Nikolaev 4 , D. Ila 3
1 Department of Bioengineering, Ege University, Bornova/ Izmir Turkey, 2 Department of Materials Science, IYTE, Urla, Izmir Turkey, 3 Center for Irradiation of Materials, Alabama A.&M. University, NORMAL, Alabama, United States, 4 , High Current Electronics Institute, Tomsk Russian Federation
Show Abstract9:00 PM - GG7.15
Chemical and Thermal Characterization of Ti+O hybrid ion implantation based Nanofabricated UHMWPE samples
Ahmet Oztarhan 1 , N. Kaya 1 , A. Ezdesir 2 , E. Urkac 3 , S. Budak 4 , C. Muntele 4 , B. Chhay 4 , E. Oks 5 , A. Nikolaev 5 , D. Ila 4
1 Department of Bioengineering, Ege University, Bornova/ Izmir Turkey, 2 Ar&Ge Dept., Petkim, Aliaga, Izmir Turkey, 3 Department of Materials Science, IYTE, Urla/Izmir Turkey, 4 Center for Irradiation of Materials, Alabama A.&M. University, NORMAL, Alabama, United States, 5 , High Current Electronics Institute, Tomsk Russian Federation
Show Abstract9:00 PM - GG7.16
Chemical and Thermal Characterization of Cr and Cr+N hybrid ion implantation based Nanofabricated UHMWPE samples
Ahmet Oztarhan 1 , N. Kaya 1 , A. Ezdesir 2 , E. Urkac 3 , S. Budak 4 , C. Muntele 4 , B. Chhay 4 , E. Oks 5 , A. Nikolaev 5 , D. Ila 4
1 Department of Bioengineering, Ege University, Bornova/ Izmir Turkey, 2 Ar&Ge Dept. , Petkim, Aliaga, Izmir Turkey, 3 Department of Materials Science, IYTE, Urla/ Izmir Turkey, 4 Center for Irradiation of Materials, Alabama A.&M. University, NORMAL, Alabama, United States, 5 , High Current Electronics Institute, Tomsk Russian Federation
Show Abstract9:00 PM - GG7.17
Fabrication of Nanoscale Gold Clusters by Low Energy Ion Irradiation
Volha Abidzina 1 , I. Tereshko 1 , I. Elkin 2 , S. Budak 3 4 , C. Muntele 4 , D. Ila 4
1 , Belarusian-Russian University, Mogilev Belarus, 2 , ‘KAMA VT’ Research and Production Enterprise, Mogilev Belarus, 3 Department of Physics, Fatih University, Istanbul Turkey, 4 , Center for Irradiation of Materials, Alabama A&M University, Normal, Alabama, United States
Show AbstractWe have applied glow discharge to generate uniform low energy ions in order to fabricate nanoscale metallic clusters on the surface of various materials including high temperature carbon composites and ceramics such as silica. In the present work we have produced nanolayer of SiO2 containing 5 to 20 atomic percent of Au. The SiO2+Au nanolayer was produced using codeposition of Au and SiO2 on suprasil. The thicknesses of the films were measured using interferometry technique and the concentration of Au was measured using the combined RBS and the thickness data from interferometry measurement. The formation of Au nanoclusters was monitored using optical absorption photospectrometry using Mie theory. The size of the Au nanoclusters were monitored using AFM since they are formed on the surface, 1nm to 10nm depending on the fabrication parameters. We also used Doyle theory to confirm the AFM data, where using the FWHM of the absorption band and Doyle theory only provides the average radius size for a group of the Au nanoclusters. In order to confirm our findings we applied a parallel process of using similar fabricated SiO2+Au nanolayer on suprasil and annealed at temperature between 900C to 1100C following the formation of optical absorption band and correlating the results with that of a similar fabricated nanolayer which is exposed to 2 to 3 keV discharged residual gas for 30 to 300 minutes while maintaining the system temperature at about 323K. We will present our findings in this meeting.
9:00 PM - GG7.18
Fluence Dependence of Thermoelectric Properties Induced By Ion Bombardment of Zn4Sb3 and CeFe2Co2Sb12 thin films
S. Budak 1 , C. Smith 2 , C. Muntele 1 , R. Zimmerman 1 , D. Ila 1
1 Center for Irradiation of Materials, Alabama A.&M. University, NORMAL, Alabama, United States, 2 , NASA MSFC, MSFC, Huntsville, Alabama, United States
Show AbstractThermoelectric power generation is a promising technology for increasing the efficiency of electrical and optical electrical devices. We prepared samples by Electron Beam evaporating Zn4Sb3 and CeFe2Co2Sb12 Thin Films on Silicon dioxide substrates. The materials were Co evaporated and then were prepared of gold over-coating. Following electron deposition we performed post Ion bombardment at a constant energy of is 5 MeV while varying fluencies ranging from 1*1012, 1*1013, 1*1014, 1*1015 ions / cm2 respectfully. The production of Nano clusters generated from the Si ion bombardment modifies the electrical and phonon interactions in the material. Also, we will report on the fluency dependence of the figure of merit, Seebeck Coefficient, Thermal Conductivity and Electrical Conductivity. In addition, Rutherford backscattering spectrometry (RBS) was used to analyze the elemental composition of the deposited material.Research sponsored by the Center for Irradiation of Materials, Alabama A&M University and by the AAMURI Center for Advanced Propulsion Materials under the contract number NAG8-1933 from NASA, and by National Science Foundation under Grant No. EPS-0447675.** Corresponding author: D. ILA; Tel.: 256-372-5866; Fax: 256-372-5868; Email:
[email protected] 9:00 PM - GG7.19
Effect of Implantation Dose and Annealing Time on the Formation of Si Nanocrystals Embedded in Thermal Oxide.
Cong Qian 1 , Zhengxuan Zhang 1
1 , Shanghai Institute of Microsystem and Information Technology, CAS, Shanghai China
Show Abstract9:00 PM - GG7.2
Ion Bombardment Improvement on Thermoelectric Properties of Multilayered Bi2Te3/Sb2Te3 Deposited by Magnetron Sputtering.
Bangke Zheng 1 , I. Muntele 1 , S. Budak 1 , R. Zimmerman 1 , C. Muntele 1 , D. Ila 1
1 Department of Physics, Alabama A&M University, , Center for Irradiation Materials , Normal, Alabama, United States
Show Abstract We have used magnetron sputtering at relatively low temperature in order to maintain uniform stoichiometry of Bi2Te3 and Sb2Te3 during deposition 70 nanolayers (quantum well device) providing desired electric and thermal conductivity better than bulk Bi2Te3 and bulk Sb2Te3. The thermal conductivity was further reduced as well as the increase in electrical conductivity using the electronics energy deposited by 5 MeV Si ions due to ionization at various fluences. The electronic energy deposited by 5 MeV Si ions support the formation of nanoscale cluster (quantum dot) structures thus confining the phonon transmission. The increase in the electron density of state of the mini-bands, which is due to formation of regimented nanoclusters, increases the Seebeck coefficient, and enhances electric conductivity, eventually increasing the thermoelectric figure of merit of the superlattice.
9:00 PM - GG7.20
Optical and Structural Properties of Ge Nanocrystals Embedded in HfO2.
Do Kyu Lee 1 , Sung Kim 1 , Phil Sung Jung 1 , Sung Won Hwang 1 , Suk-Ho Choi 1 , Robert Glen Elliman 2
1 College of Electronics and Information, Kyung Hee University, Yongin, Kyungkido, Korea (the Republic of), 2 Electronic Materials Engineering Department, Australian National University, Canberra, Australian Capital Territory, Australia
Show Abstract9:00 PM - GG7.21
Properties of Nano-layers of Nanoclusters of Ag in SiO2 Host produced by MeV Si ion bombardment *
S. Budak 1 , C. Smith 2 , C. Muntele 1 , R. Zimmerman 1 , D. Ila 1
1 Center for Irradiation of Materials, Alabama A.&M. University, NORMAL, Alabama, United States, 2 , NASA MSFC, MSFC, AL , Huntsville, Alabama, United States
Show AbstractWe prepared 50 and 100 periodic nano-layers of SiO2/AgxSiO2(1-x). The deposited multi-layer films have a periodic structure consisting of alternating layers where each layer is between 1-10 nm thick. The purpose of this research is to use generate Nanolayers of Nanocrystals of Ag with SiO2 as host and as buffer layer using a combination of codeposition and MeV ion bombardment taking advantage of the electronics energy deposited in the MeV ion track due to ionization in order to nucleate nanoclusters. Our previous work showed that these nanoclusters have crystallinity similar to the bulk material. Nanocrystals of Ag in Silica produce an absorption band at about 420 nm. Due to interaction of Nanocrystals between sequential Nanolayers there is widening of the absorption band. The optical, electrical, and thermal properties of the layered structures were studied before and after bombardment by 5 MeV Si ion at various fluences to form Nanocrystals in layers of SiO2 containing few percent of Ag. Rutherford Backscattering Spectrometry (RBS) was used to monitor the stoichiometry before and after MeV bombardments. We will present our findings.Keywords: Ion bombardment, thermoelectric properties, multi-nanolayers,SiO2/Au+SiO2, Rutherford backscattering, Van der Pauw method, 3w Method thermal conductivity measurement, Seebeck coefficient, Figure of merit*Research sponsored by the Center for Irradiation of Materials, Alabama A&M University and by the AAMURI Center for Advanced Propulsion Materials under the contract number NAG8-1933 from NASA, and by National Science Foundation under Grant No. EPS-0447675.** Corresponding author: D. ILA; Tel.: 256-372-5866; Fax: 256-372-5868; Email:
[email protected] 9:00 PM - GG7.22
Effects of MeV Si ion bombardments on the Properties of Nano-layers of SiO2/SiO2+Zn4Sb3*
S. Budak 1 , C. Smith 2 , C. Muntele 1 , R. Zimmerman 1 , D. Ila 1
1 Center for Irradiation of Materials, Alabama A.&M. University, NORMAL, Alabama, United States, 2 , NASA MSFC, MSFC, AL , Huntsville, Alabama, United States
Show AbstractWe prepared periodic nano-layers of SiO2/SiO2+Zn4Sb3. The deposited multi-layer films have a periodic structure consisting of alternating layers where each layer is between 1-10 nm thick. The purpose of this research is to use generate Nanolayers of Nanostructures of Zn4Sb3 with SiO2 as host and as buffer layer using a combination of codeposition and MeV ion bombardment taking advantage of the electronics energy deposited in the MeV ion track due to ionization in order to nucleate nanostructures. The optical, electrical, and thermal properties of the layered structures were studied before and after bombardment by 5 MeV Si ions at various fluences to form Nanostructures in layers of SiO2 containing few percent of Zn4Sb3. Rutherford Backscattering Spectrometry (RBS) was used to monitor the stoichiometry before and after MeV bombardments. We will present our findings.Keywords: Ion bombardment, thermoelectric properties, multi-nanolayers, SiO2/SiO2+Zn4Sb3, Rutherford backscattering, Van der Pauw method, 3w Method thermal conductivity measurement, Seebeck coefficient, Figure of merit*Research sponsored by the Center for Irradiation of Materials, Alabama A&M University and by the AAMURI Center for Advanced Propulsion Materials under the contract number NAG8-1933 from NASA, and by National Science Foundation under Grant No. EPS-0447675.** Corresponding author: D. ILA; Tel.: 256-372-5866; Fax: 256-372-5868; Email:
[email protected] 9:00 PM - GG7.24
High Resolution XRD Studies of Ion Beam Irradiated InGaAs/InP Multi Quantum Wells
Dhamodaran Santhanagopalan 1 , Anand Pathak 1 , Andrzej Turos 2 , Devesh Avasthi 3 , Brij Arora 4
1 School of Physics, University of Hyderabad, Hyderabad, Andra Pradesh, India, 2 , Institute of Electronic Materials Technology, ul. Wolczynska, Warsaw, Poland, 3 , Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi, India, 4 , Tata Institute of Fundamental Research, Colaba, Mumbai, India
Show AbstractMulti quantum wells of InGaAs/InP grown by metal organic chemical vapor deposition have been irradiated using swift heavy ions. Irradiation has been performed using 150MeV Ag and 200MeV Au ions. Both as-grown and irradiated samples were subjected to rapid thermal annealing at 773 and 973K for 60s. As-grown, irradiated and annealed samples were subjected to high resolution x-ray diffraction studies. Both symmetric and asymmetric scans were analyzed. The as-grown and Ag ion irradiated samples show sharp and highly ordered satellite peaks whereas, the Au ion irradiated samples show broad and low intense peaks. The higher order satellite peaks of the annealed samples vanished with increase of annealing temperature from 773 to 973K, indicating mixing induced interfacial disorder. Annealing of irradiated samples show higher mixing and disorder and no higher order satellite peaks were observed. Negligible strain was observed after high temperature annealing of as grown samples. Strain values calculated from the X-ray studies indicate that the irradiated samples have higher strain which has been reduced upon annealing. This indicates that the annealing induced mixing occurs maintaining the lattice parameter close to that of the substrate. The effect of electronic energy loss for interface mixing has been discussed in detail. The role of incident ion fluence in combination with the electronic energy loss will also be discussed in detail. The results have been compared with the literature and discussed in detail.
9:00 PM - GG7.3
Surface Patterning for Nanowire Growth.
D. Walker 3 , S. Budak 2 , C. Muntele 2 , A. Elsamedicy 3 , R. Zimmerman 2 , D. Ila 2
3 Dept. of Physics, Univ. Of Alabama at Huntsville, Huntsville, Alabama, United States, 2 Ctr. For Irradiation, Alabama A&M University, Normal, Alabama, United States
Show Abstract9:00 PM - GG7.5
Nanoscale Surface Modification of UltraHigh Molecular Weight Polyethylene (UHMWPE) Samples with the W + C Ion Implantation
E. Urkac 2 , Ahmet Oztarhan 3 , F. Tihminlioglu 2 , N. Kaya 3 , S. Budak 1 , C. Muntele 1 , E. Oks 4 , A. Nikolaev 4 , D. Ila 1
2 Department of Materials Science, IYTE, Urla Turkey, 3 Department of Bioengineering, Ege University, Izmir Turkey, 1 Center for Irradiation of Materials, Alabama A.&M. University, NORMAL, Alabama, United States, 4 , High Current Electronics Institute, Tomsk Russian Federation
Show Abstract In this work, UHMWPE samples were W + C ion implanted by using MEVVA ion implantation technique. Samples were implanted with W and C atoms with a fluence of 10 17 ion/cm2 and extraction voltage of 30 kV. Mechanism underlies this modification characterized with Raman Spectra, ATR-FTIR, UV-VIS-NIR Spectrum and RBS . Surface morphology of implanted and unimplanted samples were examined in nanoscale with AFM. It is thought that the hydrogen content at the UHMWPE surface decreased and the chain structure was damaged as a result of W+C ion implantation. Results will be presented and discussed.
9:00 PM - GG7.6
Formation of Surface Nanostructures on Implantation of Cluster ions into Silicon, Sapphire and Graphite.
Vladimir Popok 1 , Sasa Vuckovic 1 , Eleanor Campbell 1
1 Department of Physics, Gothenburg University, Gothenburg Sweden
Show Abstract9:00 PM - GG7.7
Irradiation Effects of Methanol Cluster Ion Beams on Solid Surfaces.
Gikan Takaoka 1 , Masakazu Kawashita 1 , Takeshi Okada 1
1 Ion Beam Eng. Exp. Lab., Kyoto University, Kyoto Japan
Show Abstract9:00 PM - GG7.8
Nano- and Micro-Structural Evolution of UHMWPE by Ion Beam.
F. Calzzani 1 , B. Chhay 1 , C. Muntele 1 , Robert Zimmerman 1 , A. Ostarhan 1 , Daryush Ila 1
1 Center for Irradiation of Materials, Alabama A&M University, Normal, Alabama, United States
Show AbstractIt is important to produce uniform nano-patterns with no possibility of surface exfoliation on polyethylene devices used in aerospace and in medical industry. We studied the change in the surface morphology of Polyethylene at nanoscale using both keV and MeV ion beam. We have investigated the change in the surface morphology before and after ion bombardment as well as before and after ion implantation. We have made an attempt to change the morphology to produce a uniform surface with reduced cracks and reduced granularity. For this process we have chosen HDPE, regular PE as well as Ultra-high-molecular-weight Polyethylene (UHMWPE). Coupons of these materials were exposed to various fluences of keV Ar ions, MeV Au Ions, and combinations of MeV Au and keV Ar ion beam. The surface morphology and the change in the chemical structure was studied using scanning micro Raman, FTIR, AFM and SEM. We will present our findings in this meeting.Acknowledgement: Research sponsored by the Center for Irradiation of Materials, Alabama A&M University and by the AAMURI Center for Advanced Propulsion Materials under the contract number NNM06AA12A from NASA, and by National Science Foundation under Grant No. EPS-0447675.* Corresponding author: D. ILA; Tel.: 256-372-5866; Fax: 256-372-5868; Email:
[email protected] 9:00 PM - GG7.9
MeV Ion-Beam Bombardments Effects on The Thermoelectric Figures of Merit of Zn4Sb3 and ZrNiSn-Based half-heusler compounds*
S. Budak 1 , C. Smith 2 , C. Muntele 1 , R. Zimmerman 1 , D. Ila 1
1 Center for Irradiation of Materials, Alabama A.&M. University, NORMAL, Alabama, United States, 2 , NASA MSFC, MSFC, AL , Huntsville, Alabama, United States
Show AbstractSemiconducting β-Zn4Sb3 and ZrNiSn-based half-heusler compound thin films were prepared by co-evaporation followed by a high-temperature thermal annealing for the application of thermoelectric (TE) materials. High-purity solid zinc and antimony were evaporated by electron beam to grow the β-Zn4Sb3 thin film while high-purity zirconium nickel powder and solid tin were evaporated by electron beam to grow the ZrNiSn-based half-heusler compound thin film. After the growth of films, a high-temperature thermal anneal was performed with flowing of argon gas to produce the desired stoichiometry and crystal structures of films. Rutherford backscattering spectrometry (RBS) was used to analyze the composition of thin films. The grown thin films were subjected to MeV Si ion bombardments for generation of nanostructures in the films. We measured the thermal conductivity, Seebeck coefficient, and electrical conductivity of these two systems before and after bombardment by MeV Si ion beam. The two material systems have been identified as promising TE materials for the application of thermal-to-electrical energy conversion, but the efficiency still limits their applications. Our experience shows that electronic energy deposited due to ionization in the track of MeV ion beam can cause localized crystallization. The nanostructures produced by MeV ion beam can cause significant change in both electrical and thermal conductivity of thin films, thereby improving the efficiency. We used a house developed 3ω-method measurement system to measure the thermal conductivity and a (MMR) Hall measurement system to measure the electrical conductivity and a (MMR) Seebeck-coefficient measurement system to measure the Seebeck coefficient. The thermoelectric figures of merit of the two material systems were then derived by calculations using the measurement results. The MeV ion-beam bombardment was found to decrease the thermal conductivity of thin films and increase the efficiency of thermal-to-electrical energy conversion.Acknowledgement: *Research sponsored by the Center for Irradiation of Materials, Alabama A&M University and by the AAMURI Center for Advanced Propulsion Materials under the contract number NAG8-1933 from NASA, and by National Science Foundation under Grant No. EPS-0447675. * Corresponding author: D. ILA; Tel.: 256-372-5866; Fax: 256-372-5868; Email:
[email protected]