The Experts below are selected from a list of 300 Experts worldwide ranked by ideXlab platform
Toshio Seki - One of the best experts on this subject based on the ideXlab platform.
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precise and fast secondary Ion mass spectrometry depth profiling of polymer materials with large ar cluster Ion Beams
Rapid Communications in Mass Spectrometry, 2009Co-Authors: Satoshi Ninomiya, Toshio Seki, Takaaki Aoki, Kazuya Ichiki, Hideaki Yamada, Yoshihiko Nakata, Jiro MatsuoAbstract:We demonstrate depth profiling of polymer materials by using large argon (Ar) cluster Ion Beams. In general, depth profiling with secondary Ion mass spectrometry (SIMS) presents serious problems in organic materials, because the primary keV atomic Ion Beams often damage them and the molecular Ion yields decrease with increasing incident Ion fluence. Recently, we have found reduced damage of organic materials during sputtering with large gas cluster Ions, and reported on the unique secondary Ion emissIon of organic materials. Secondary Ions from the polymer films were measured with a linear type time-of-flight (TOF) technique; the films were also etched with large Ar cluster Ion Beams. The mean cluster size of the primary Ion Beams was Ar700 and incident energy was 5.5 keV. Although the primary Ion fluence exceeded the static SIMS limit, the molecular Ion intensities from the polymer films remained constant, indicating that irradiatIon with large Ar cluster Ion Beams rarely leads to damage accumulatIon on the surface of the films, and this characteristic is excellently suitable for SIMS depth profiling of organic materials. Copyright © 2009 John Wiley & Sons, Ltd.
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Nano-processing with gas cluster Ion Beams
Surface and Coatings Technology, 2009Co-Authors: Toshio SekiAbstract:The gas cluster Ion beam process has become a candidate technique for advanced nano-fabricatIon, where both throughput and precise functIonality are required. It is demonstrated that both extreme high-speed and precise nano-processing with low damage can be realized using reactive cluster Ion Beams. To date, this technique has been successfully applied to photonic, magnetic, electronic, and biological materials processing. The energy and size of cluster have become well controllable and many kinds of gaseous materials become available as cluster source gas. The fundamentals and applicatIons of gas cluster Ion beam process are reviewed in this paper. ?? 2009 Elsevier B.V. All rights reserved.
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Surface processing with high-energy gas cluster Ion Beams
Surface and Coatings Technology, 2007Co-Authors: Toshio Seki, J. MatsuoAbstract:Gas cluster Ion Beams can produce high rate sputtering with low damage compared with the more familiar monomer Ion beam process. In order to realize high-speed surface processing, a high-energy gas cluster Ion beam irradiatIon system was developed in which high-energy Ar cluster Ion Beams were generated. The mean size of the Ar cluster was about 1800 atoms, as measured using the time-of-flight (TOF) method. Si substrates were irradiated with the Ar cluster Ions at acceleratIon energies between 20 and 80 keV. The sputtering yield increased with acceleratIon energy and reached about 230 atoms/Ion at 80 keV, a value about 180 times higher than that of Ar monomer Ions. Au films were also irradiated at acceleratIon energies between 20 and 80 keV and the surfaces were observed with Atomic Force Microscopy (AFM). The high-energy cluster Ion irradiatIon caused a decrease in surface roughness. These results indicate that high-speed smooth etching can be realized with high-energy cluster Ion Beams. This processing method can be applied to fabricate nano-devices. © 2007 Elsevier B.V. All rights reserved.
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Energy distributIons of high current cluster Ion Beams
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2005Co-Authors: Toshio Seki, J. MatsuoAbstract:The cluster Ion beam processes has been shown to produce new surface modificatIon effects, such as surface smoothing, high rate sputtering and very shallow implantatIon. Now high current is needed to increase the productivity of cluster processing. However, the chamber pressure increases with cluster beam intensity. Energy distributIons of the cluster Ion Beams show that both size and energy of cluster Ion decrease by numerous collisIons with residual gas. This indicates that it is necessary to reduce the chamber pressure for effective transport of cluster Ion Beams. © 2005 Elsevier B.V. All rights reserved.
J. Matsuo - One of the best experts on this subject based on the ideXlab platform.
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Surface processing with high-energy gas cluster Ion Beams
Surface and Coatings Technology, 2007Co-Authors: Toshio Seki, J. MatsuoAbstract:Gas cluster Ion Beams can produce high rate sputtering with low damage compared with the more familiar monomer Ion beam process. In order to realize high-speed surface processing, a high-energy gas cluster Ion beam irradiatIon system was developed in which high-energy Ar cluster Ion Beams were generated. The mean size of the Ar cluster was about 1800 atoms, as measured using the time-of-flight (TOF) method. Si substrates were irradiated with the Ar cluster Ions at acceleratIon energies between 20 and 80 keV. The sputtering yield increased with acceleratIon energy and reached about 230 atoms/Ion at 80 keV, a value about 180 times higher than that of Ar monomer Ions. Au films were also irradiated at acceleratIon energies between 20 and 80 keV and the surfaces were observed with Atomic Force Microscopy (AFM). The high-energy cluster Ion irradiatIon caused a decrease in surface roughness. These results indicate that high-speed smooth etching can be realized with high-energy cluster Ion Beams. This processing method can be applied to fabricate nano-devices. © 2007 Elsevier B.V. All rights reserved.
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Energy distributIons of high current cluster Ion Beams
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2005Co-Authors: Toshio Seki, J. MatsuoAbstract:The cluster Ion beam processes has been shown to produce new surface modificatIon effects, such as surface smoothing, high rate sputtering and very shallow implantatIon. Now high current is needed to increase the productivity of cluster processing. However, the chamber pressure increases with cluster beam intensity. Energy distributIons of the cluster Ion Beams show that both size and energy of cluster Ion decrease by numerous collisIons with residual gas. This indicates that it is necessary to reduce the chamber pressure for effective transport of cluster Ion Beams. © 2005 Elsevier B.V. All rights reserved.
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Surface modificatIon with gas cluster Ion Beams from fundamental characteristics to applicatIons
Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms, 2004Co-Authors: NAOMI TOYODA, J. Matsuo, Iaso YamadaAbstract:Gas cluster Ion beam (GCIB) processing has been applied for the ultra-smooth surfaces preparatIon recently. As GCIB exhibit significantly different physical phenomena from atomic or molecular Ion Beams, new fields of Ion Beams have been developed by using GCIB. In this paper, fundamental characteristics of GCIB will be summarized and surface smoothing applicatIons are explained. AdditIonally, it has been shown that GCIB is suited for assisting Ion Beams during thin film depositIons. Recent results of GCIB assisted depositIons are also summarized in the latter part of this paper. © 2003 Elsevier B.V. All rights reserved.
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Secondary Ion mass spectrometry with gas cluster Ion Beams
Nuclear Instruments and Methods in Physics Research Section B, 2002Co-Authors: NAOMI TOYODA, Iaso Yamada, J. Matsuo, Takaaki Aoki, D.B.a FennerAbstract:Secondary Ion mass spectrometry (SIMS) with gas cluster Ion Beams was studied with experiments and molecular dynamics (MD) simulatIons to achieve a high-resolutIon depth profiling. For this purpose, it is important to prevent both Ion mixing and the surface roughening due to energetic Ions. As the Ar cluster Ion Beams shows high secondary Ion yield and surface smoothing effects in the low-energy regime, it is suitable for the primary Ion beam of SIMS. From MD simulatIons of Ar cluster Ion impact on Si, Ion mixing is heavier than than those for Ar monomer Ions at the same energy per atom, because the energy density at the impact point is extremely high. However, the sputtering yields with Ar cluster Ions are one or two orders of magnitude higher than that with Ar monomer Ions at the same energy per atom. Comparing at the Ion energy where the Ion-mixing depths are the same by both Ar cluster and Ar monomer Ions, cluster Ions show almost 10 times higher sputtering yield than by Ar monomer Ions. A preliminary experiment of SIMS with Ar cluster Ion was performed and a mass resolutIon of several nm was achieved for a Ta film. ?? 2002 Published by Elsevier Science B.V.
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Surface processing by gas cluster Ion Beams
ION IMPLANTATION TECHNOLOGY - 96, 1997Co-Authors: NAOMI TOYODA, J. Matsuo, Iaso YamadaAbstract:Surface processing with gas cluster Ion Beams which contain hundreds or\neven many thousands of atoms or molecules has been studied. The\nsputtering yields of various materials with Ar cluster Ions are about\none order of magnitude higher than those produced by Ar monomer Ions\nwith the same energy. Also, the sputtering yields of Si and W are\nchemically enhanced with SF6 cluster Ion Beams.\nThe surface roughness of Cu dramatically decreased when bombarded with\nAr cluster Ion Beams compared with Ar monomer Ion Beams, and there is no\nroughening mechanism. This smoothing effect of gas cluster Ion Beams is\napplicable for very hard materials, such as CVD diamond films.
Iaso Yamada - One of the best experts on this subject based on the ideXlab platform.
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Surface modificatIon with gas cluster Ion Beams from fundamental characteristics to applicatIons
Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms, 2004Co-Authors: NAOMI TOYODA, J. Matsuo, Iaso YamadaAbstract:Gas cluster Ion beam (GCIB) processing has been applied for the ultra-smooth surfaces preparatIon recently. As GCIB exhibit significantly different physical phenomena from atomic or molecular Ion Beams, new fields of Ion Beams have been developed by using GCIB. In this paper, fundamental characteristics of GCIB will be summarized and surface smoothing applicatIons are explained. AdditIonally, it has been shown that GCIB is suited for assisting Ion Beams during thin film depositIons. Recent results of GCIB assisted depositIons are also summarized in the latter part of this paper. © 2003 Elsevier B.V. All rights reserved.
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Surface smoothing of compound semiconductor substrates with gas cluster Ion Beams
APPLICATION OF ACCELERATORS IN RESEARCH AND INDUSTRY, 2003Co-Authors: Shingo Houzumi, NAOMI TOYODA, Iaso YamadaAbstract:Surface smoothing by gas cluster Ion Beams (GCIB) was studied for\ncompound semiconductor such as GaN and SiC. Average cluster size of Ar\ncluster Ions was 2000atoms/cluster measured by time of flight (TOF).\nSince the total acceleratIon energy was 20keV, the energy per atom was\n10eV/atom. This low-energy characteristic of gas cluster Ion Beams is\ndesirable for compound semiconductors. GLIB irradiatIon was employed to\nremove the scratches of the mechanically polished SiC surface. After\nirradiatIon at acceleratIon energy of 15keV, the scratches was completry\nremoved. The GaN film with initial average roughness of 4nm was also\nsmoothed to that of 1.4nm by Ar cluster Ion Beams. Furthermore SiC\nsubstrates were irradiated with SF6 cluster Ions. The sputtering yield\nof SiC with SF6 cluster Ions was enhanced almost 3 times than that with\nAr cluster Ions.
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Secondary Ion mass spectrometry with gas cluster Ion Beams
Nuclear Instruments and Methods in Physics Research Section B, 2002Co-Authors: NAOMI TOYODA, Iaso Yamada, J. Matsuo, Takaaki Aoki, D.B.a FennerAbstract:Secondary Ion mass spectrometry (SIMS) with gas cluster Ion Beams was studied with experiments and molecular dynamics (MD) simulatIons to achieve a high-resolutIon depth profiling. For this purpose, it is important to prevent both Ion mixing and the surface roughening due to energetic Ions. As the Ar cluster Ion Beams shows high secondary Ion yield and surface smoothing effects in the low-energy regime, it is suitable for the primary Ion beam of SIMS. From MD simulatIons of Ar cluster Ion impact on Si, Ion mixing is heavier than than those for Ar monomer Ions at the same energy per atom, because the energy density at the impact point is extremely high. However, the sputtering yields with Ar cluster Ions are one or two orders of magnitude higher than that with Ar monomer Ions at the same energy per atom. Comparing at the Ion energy where the Ion-mixing depths are the same by both Ar cluster and Ar monomer Ions, cluster Ions show almost 10 times higher sputtering yield than by Ar monomer Ions. A preliminary experiment of SIMS with Ar cluster Ion was performed and a mass resolutIon of several nm was achieved for a Ta film. ?? 2002 Published by Elsevier Science B.V.
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Novel materials processing and applicatIons by gas cluster Ion Beams
The European Physical Journal D, 1999Co-Authors: Iaso YamadaAbstract:Gas cluster Ion Beams are found to offer a number of new and important opportunities for processing of materials. Ultrashallow Ion implantatIon by cluster Ion Beams has been demonstrated experimentally and confirmed by molecular dynamics simulatIons. Very high-rate sputtering, with sputtering yields of one or two orders of magnitude greater than those produced by monomer Ion Beams, has also been studied in detail. Surfaces sputtered by cluster Ion Beams become smoother when physical sputtering is provided by nonreactive gas species, but chemical sputtering by reactive gases does not produce the same reductIon in roughness effect. The smoothing effects produced by cluster Ions cannot be produced by monomer Ion Beams. Unique bombarding characteristics of cluster Ion Beams have been applied to the formatIon of source/drain shallow junctIons for 40 nm p-MOSFETs, to high-yield etching and surface smoothing of Si, YBCO, diamond, and SiC substrates, and to the productIon of electronic and optical devices. A low-temperature thin-film formatIon technique by cluster Ion-assisted depositIon has also been developed for high-quality oxide films. This paper reviews recent equipment development and discusses several new applicatIons.
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Surface processing by gas cluster Ion Beams
ION IMPLANTATION TECHNOLOGY - 96, 1997Co-Authors: NAOMI TOYODA, J. Matsuo, Iaso YamadaAbstract:Surface processing with gas cluster Ion Beams which contain hundreds or\neven many thousands of atoms or molecules has been studied. The\nsputtering yields of various materials with Ar cluster Ions are about\none order of magnitude higher than those produced by Ar monomer Ions\nwith the same energy. Also, the sputtering yields of Si and W are\nchemically enhanced with SF6 cluster Ion Beams.\nThe surface roughness of Cu dramatically decreased when bombarded with\nAr cluster Ion Beams compared with Ar monomer Ion Beams, and there is no\nroughening mechanism. This smoothing effect of gas cluster Ion Beams is\napplicable for very hard materials, such as CVD diamond films.
Jiro Matsuo - One of the best experts on this subject based on the ideXlab platform.
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precise and fast secondary Ion mass spectrometry depth profiling of polymer materials with large ar cluster Ion Beams
Rapid Communications in Mass Spectrometry, 2009Co-Authors: Satoshi Ninomiya, Toshio Seki, Takaaki Aoki, Kazuya Ichiki, Hideaki Yamada, Yoshihiko Nakata, Jiro MatsuoAbstract:We demonstrate depth profiling of polymer materials by using large argon (Ar) cluster Ion Beams. In general, depth profiling with secondary Ion mass spectrometry (SIMS) presents serious problems in organic materials, because the primary keV atomic Ion Beams often damage them and the molecular Ion yields decrease with increasing incident Ion fluence. Recently, we have found reduced damage of organic materials during sputtering with large gas cluster Ions, and reported on the unique secondary Ion emissIon of organic materials. Secondary Ions from the polymer films were measured with a linear type time-of-flight (TOF) technique; the films were also etched with large Ar cluster Ion Beams. The mean cluster size of the primary Ion Beams was Ar700 and incident energy was 5.5 keV. Although the primary Ion fluence exceeded the static SIMS limit, the molecular Ion intensities from the polymer films remained constant, indicating that irradiatIon with large Ar cluster Ion Beams rarely leads to damage accumulatIon on the surface of the films, and this characteristic is excellently suitable for SIMS depth profiling of organic materials. Copyright © 2009 John Wiley & Sons, Ltd.
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surface treatment of diamond films with ar and o2 cluster Ion Beams
Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms, 1999Co-Authors: Noriaki Toyoda, Norihisa Hagiwara, Jiro Matsuo, Isao YamadaAbstract:Abstract IrradiatIon effects of Ar and O2 cluster Ion Beams were studied on Chemical Vapor DepositIon (CVD) diamond films. When the acceleratIon energy of the O2 cluster Ion was 20 keV, the sputtering yield was 400 atoms/cluster which is 13 times higher than that of Ar cluster Ions because of the enhancement by chemical reactIons. The average roughness of the diamond surface decreased with Ar cluster Ion Beams. This smoothing is attributed to the physical sputtering effect. However, a thin graphite layer was formed on the surface by contaminatIon of monomer Ion in the cluster beam, which decreases the optical transmittance of the diamond films. In contrast, the surface roughness was not improved but no graphite layer was formed with O2 cluster Ions. By using both Ar and O2 cluster Ion Beams, a very flat diamond surface without a graphite layer on the surface can be fabricated.
J C Fernandez - One of the best experts on this subject based on the ideXlab platform.
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efficient quasi monoenergetic Ion Beams from laser driven relativistic plasmas
Nature Communications, 2015Co-Authors: Sasi Palaniyappan, C Huang, D C Gautier, Christopher E Hamilton, Miguel A Santiago, Christian Kreuzer, A B Sefkow, R C Shah, J C FernandezAbstract:Table-top laser-plasma Ion accelerators have many potential applicatIons, but achieving simultaneous narrow energy spread and high efficiency remains a challenge. Here, the authors produce Ion Beams with up to 18 MeV per nucleon whilst keeping the energy spread reduced through a self-organized process.
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fast ignitIon with laser driven proton and Ion Beams
Nuclear Fusion, 2014Co-Authors: J C Fernandez, Markus Roth, B J Albright, M E Foord, B M Hegelich, J J Honrubia, R B StephensAbstract:FusIon fast ignitIon (FI) initiated by a laser-driven particle beam promises a path to high-yield and high-gain for inertial fusIon energy. FI can readily leverage the proven capability of inertial confinement fusIon (ICF) drivers, such as the NatIonal IgnitIon Facility, to assemble DT fusIon fuel at the relevant high densities. FI provides a truly alternate route to ignitIon, independent of the difficulties with achieving the ignitIon hot spot in conventIonal ICF. FI by laser-driven Ion Beams provides attractive alternatives that sidestep the present difficulties with laser-driven electron-beam FI, while leveraging the extensive recent progress in generating Ion Beams with high-power density on existing laser facilities. Whichever the Ion species, the ignitIon requirements are similar: delivering a power density ≈1022 W cm−3 (∼10 kJ in ≈20 ps within a volume of linear dimensIon ≈20 µm), to the DT fuel compressed to ∼400 g cm−3 with areal density ∼2 g cm−2. High-current, laser-driven Beams of many Ion species are promising candidates to deliver such high-power densities. The reason is that high energy, high-power laser drivers can deliver high-power fluxes that can efficiently make Ion Beams that are born neutralized in ∼fs–ps timescales, making them immune to the charge and current limits of conventIonal Beams. In summary, we find that there are many possible paths to success with FI based on laser-driven Ion Beams. Although many Ion species could be used for ignitIon, we concentrate here on either protons or C Ions, which are technologically convenient species. We review the work to date on FI design studies with those species. We also review the tremendous recent progress in discovering, characterizing and developing many Ion-acceleratIon mechanisms relevant to FI. We also summarize key recent technological advances and methods underwriting that progress. Based on the design studies and on the increased understanding of the physics of laser-driven Ion acceleratIon, we provide laser and Ion-generatIon laser-target design points based on several distinct Ion-acceleratIon mechanisms.
