Faculty Profiles - TSUTSUMI Takayoshi

Papers - TSUTSUMI Takayoshi

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Effect of electrical stimulation on proliferation and bone-formation by osteoblast-like cells cultured on carbon nanowalls scaffolds

Tsutsumi Takayoshi

Applied Physics Express Vol. 12 ( 2 ) 2019.2

Narrow free-standing features fabricated by top-down self-limited trimming of organic materials using precisely temperature-controlled plasma etching system

Tsutsumi Takayoshi

Japanese Journal of Applied Physics Vol. 58 ( 2 ) 2019.2

Modifications of surface and bulk properties of magnetron-sputtered carbon films employing a post-treatment of atmospheric pressure plasma Reviewed

Borude Ranjit R., Sugiura Hirotsugu, Ishikawa Kenji, Tsutsumi Takayoshi, Kondo Hiroki, Han Jeon Geon, Hori Masaru

JAPANESE JOURNAL OF APPLIED PHYSICS Vol. 58 ( SA ) 2019.2

Effects of Ion Bombardment Energy Flux on Chemical Compositions and Structures of Hydrogenated Amorphous Carbon Films Grown by a Radical-Injection Plasma-Enhanced Chemical Vapor Deposition Reviewed Open Access

H. Sugiura, H. Kondo, T. Tsutsumi, K. Ishikawa, M. Hori

C Vol. 5 ( 1 ) page： 8 2019.1

Electrochemical Reaction in Hydrogen Peroxide and Structural Change of Platinum Nanoparticle-Supported Carbon Nanowalls Grown Using Plasma-Enhanced Chemical Vapor Deposition Reviewed Open Access

Masakazu Tomatsu , Mineo Hiramatsu, Hiroki Kondo, Kenji Ishikawa, Takayoshi Tsutsumi, Makoto Sekine, Masaru Hori

C Vol. 5 ( 1 ) page： 7 2019.1

Polyethylene terephthalate (PET) surface modification by VUV and neutral active species in remote oxygen or hydrogen plasmas Reviewed

Yan Zhang, Kenji Ishikawa, Miran Mozetič, Takayoshi Tsutsumi, Hiroki Kondo, Makoto Sekine, Masaru Hori

Plasma Processes and Polymers 2019.1

Pt nanoparticle-supported carbon nanowalls electrode with improved durability for fuel cell applications using C2F6/H-2 plasma-enhanced chemical vapor deposition

Imai Shun, Kondo Hiroki, Hyungjun Cho, Ishikawa Kenji, Tsutsumi Takayoshi, Sekine Makoto, Hiramatsu Mineo, Hori Masaru

APPLIED PHYSICS EXPRESS Vol. 12 ( 1 ) 2019.1

Language：English Publishing type：Research paper (scientific journal) Publisher：IOP PUBLISHING LTD

The electrochemical durability of Pt nanoparticles-supported carbon nanowalls (Pt/CNWs) determined from potential cycle tests was 88% performance after 20 000 cycles and 50% performance around 140 000 cycles when the CNWs were fabricated by the C2F6/H-2 plasma-enhanced chemical vapor deposition system (C2F6-CNWs). Even after the extended start/stop-simulation tests of fuel cell Pt/C2F6-CNWs, Pt was aggregated; however, the morphological structure of the CNWs was maintained and no corrosion was evident from scanning electron microscopy observations and Raman analysis. For graphene-based catalyst supports, i.e., the Pt/C2F6-CNWs, graphene crystallinity is essential to extend electrochemical durability by inhibiting corrosion during fuel cell operation. (C) 2018 The Japan Society of Applied Physics

DOI： 10.7567/1882-0786/aaf0ab

Web of Science

Reaction mechanisms between chlorine plasma and a spin-on-type polymer mask for high-temperature plasma etching Reviewed

Zhang Yan, Imamura Masato, Ishikawa Kenji, Tsutsumi Takayoshi, Kondo Hiroki, Sekine Makoto, Hori Masaru

JAPANESE JOURNAL OF APPLIED PHYSICS Vol. 57 ( 10 ) 2018.10

Temperature dependence on plasma-induced damage and chemical reactions in GaN etching processes using chlorine plasma Reviewed

Zecheng Liu, Kenji Ishikawa, Masato Imamura, Takayoshi Tsutsumi, Hiroki Kondo, Osamu Oda, Makoto Sekine, Masaru Hori

Japanese Journal of Applied Physics Vol. 57 ( 6 ) 2018.6

Language：English Publishing type：Research paper (international conference proceedings) Publisher：Japan Society of Applied Physics

Plasma-induced damage (PID) on GaN was optimally reduced by high-temperature chlorine plasma etching. Energetic ion bombardments primarily induced PID involving stoichiometry, surface roughness, and photoluminescence (PL) degradation. Chemical reactions under ultraviolet (UV) irradiation and chlorine radical exposure at temperatures higher than 400 °C can be controlled by taking into account the synergism of simultaneous photon and radical irradiations to effectively reduce PID.

DOI： 10.7567/JJAP.57.06JD01

Web of Science

Scopus

Effects of gas residence time of CH4/H2 on sp2 fraction of amorphous carbon films and dissociated methyl density during radical-injection plasma-enhanced chemical vapor deposition Reviewed

Hirotsugu Sugiura, Lingyun Jia, Hiroki Kondo, Kenji Ishikawa, Takayoshi Tsutsumi, Toshio Hayashi, Keigo Takeda, Makoto Sekine, Masaru Hori

Japanese Journal of Applied Physics Vol. 57 ( 6 ) 2018.6

Language：English Publishing type：Research paper (international conference proceedings) Publisher：Japan Society of Applied Physics

Quadruple mass spectrometric measurements of CH3 density during radical-injection plasma-enhanced chemical vapor deposition to consider the sp2 fraction of amorphous carbon (a-C) films were performed. The sp2 fraction of the a-C films reached a minimum of 46%, where the CH3 density was maximum for a residence time of 6 ms. The sp2 fraction of the a-C films was tailored with the gaseous phase CH3 density during the deposition. This knowledge is useful for understanding the formation mechanism of bonding structures in the a-C films, which enables the precise control of their electronic properties.

DOI： 10.7567/JJAP.57.06JE03

Web of Science

Scopus

Nanographene synthesis employing in-liquid plasmas with alcohols or hydrocarbons Reviewed

Atsushi Ando, Kenji Ishikawa, Hiroki Kondo, Takayoshi Tsutsumi, Keigo Takeda, Takayuki Ohta, Masafumi Ito, Mineo Hiramatsu, Makoto Sekine, Masaru Hori

Japanese Journal of Applied Physics Vol. 57 ( 2 ) 2018.2

Language：English Publishing type：Research paper (scientific journal) Publisher：Japan Society of Applied Physics

Graphenes of nanometer-scale grain size (nanographenes) were synthesized using in-liquid plasmas with alcohols or hydrocarbons. This method of nanographene synthesis showed a trade-off relationship between crystallinity and synthesis rate. The high crystallinity of nanographenes synthesized with alcohols was evaluated from the small full width at half maxima (FWHM) of the G band in Raman scattering spectra. On the other hand, in the case of using hydrocarbons such as n-hexane and benzene, a significantly high synthesis rate was obtained but the crystallinity of nanographenes was low. It was found that hydroxyl groups and oxygen atoms of liquid sources play important roles in determining the crystallinity of synthesized nanographenes.

DOI： 10.7567/JJAP.57.026201

Web of Science

Scopus

Rapid growth of micron-sized graphene flakes using in-liquid plasma employing iron phthalocyanine-added ethanol Reviewed

Tomoki Amano, Hiroki Kondo, Kenji Ishikawa, Takayoshi Tsutsumi, Keigo Takeda, Mineo Hiramatsu, Makoto Sekine, Masaru Hori

Applied Physics Express Vol. 11 ( 1 ) 2018.1

Language：English Publishing type：Research paper (scientific journal) Publisher：Japan Society of Applied Physics

Giant graphene flakes on the micron scale were synthesized and grown in plasmas in liquid-phase pure ethanol with added iron phthalocyanine (FePc) in a solvent. At atmospheric pressure, plasmas were generated in the gas phase filled with Ar and in the liquid phases comprising bubbles and liquid solutions. In the mixture of FePc in ethanol, nanographene sheets aggregated to form giant graphene flakes, as confirmed by the D, G, and 2D bands in the corresponding Raman spectra. Therefore, a bottom-up approach of graphite synthesis from pure ethanol with additives and a catalyst was realized by in-liquid plasma processing.

DOI： 10.7567/APEX.11.015102

Web of Science

Scopus

Real-time control of a wafer temperature for uniform plasma process

Tsutsumi T., Fuknaga Y., Ishikawa K., Kondo H., Sekine M., Hori M.

2018 INTERNATIONAL SYMPOSIUM ON SEMICONDUCTOR MANUFACTURING (ISSM) page： . 2018

Measurement of F-, O- and CF3- densities in 60 and 100 MHz asymmetric capacitively coupled plasma discharge produced in an Ar/O2/C4F8 gas mixture Reviewed

N. Sirse, T. Tsutsumi, M. Sekine, M. Hori, A. R. Ellingboe

Journal of Physics D: Applied Physics Vol. 50 ( 33 ) page： 335205 2017.7

Temperature dependence of protection layer formation on organic trench sidewall in H2/N2 plasma etching with control of substrate temperature Reviewed

Y. Fukunaga, T. Tsutsumi, K. Takeda, H. Kondo, K. Ishikawa, M. Sekine, M. Hori

Japanese Journal of Applied Physics Vol. 56 ( 7 ) page： 076202 2017.6

Investigation of the radially resolved oxygen dissociation degree and local mean electron energy in oxygen plasmas in contact with different surface materials Reviewed Open Access

T. Tsutsumi, A. Greb, A. R. Gibson, M. Hori, D. O'Connell, T. Gans

Journal of Applied Physics Vol. 121 ( 14 ) page： 143301 2017.4

Electron behaviors in afterglow of synchronized dc-imposed pulsed fluorocarbon-based plasmas Reviewed

T. Ueyama, Y. Fukunaga, T. Tsutsumi, K. Takeda, H. Kondo, K. Ishikawa, M. Sekine, M. Iwata, Y. Ohya, H. Sugai, M. Hori

Japanese Journal of Applied Physics Vol. 56 ( 6S2 ) page： 06HC03 2017.3

Absolute density of precursor SiH₃ radicals and H atoms in H2-diluted SiH₄ gas plasma for deposition of microcrystalline silicon films Reviewed Open Access

Y. Abe, K. Ishikawa, K. Takeda, T. Tsutsumi, A. Fukushima, H. Kondo, M. Sekine, M. Hori

Applied Physics Letters Vol. 110 ( 4 ) page： 043902 2017.1

Advanced Plasma Etching Processing: Atomic Layer Etching for Nanoscale Devices Reviewed

T. Tsutsumi, M. Zaitsu, A. Kobayashi, N. Kobayashi, M. Hori

PLASMA NANO SCIENCE AND TECHNOLOGY Vol. 77 ( 3 ) page： 25 - 28 2017

Language：English Publishing type：Research paper (international conference proceedings) Publisher：ELECTROCHEMICAL SOC INC

Plasma processes for deposition and etching are required for development of the next generation semiconductor devices. To achieve high performance of nanoscale devices, the continuous development of fabrication processes is necessary. An atomic layer etching (ALE) process achieves this continuous development, since the process has advantages such as more precise, higher controllability and repeatability. We have developed ALE process for SiO2 to achieve high controllability and repeatability. The ALE process is a cyclic process composed of two steps: a first step which deposits a fluorocarbon film on the SiO2 surface using an Ar/C4F8 plasma, followed by an O-2 plasma etching step. The O-2 plasma etching suppresses forming a carbon-rich film on the target material surface and maintains the chamber conditions by removing the fluorocarbon on the chamber walls. The ALE process for SiO2 exhibits high reproducibility and has the potential to allow uniform EPC values over large wafer surfaces.

DOI： 10.1149/07703.0025ecst

Web of Science

Atomic layer etching of SiO₂ by alternating an O₂ plasma with fluorocarbon film deposition Reviewed Open Access

T. Tsutsumi, H. Kondo, M. Hori, M. Zaitsu, A. Kobayashi, T. Nozawa, N. Kobayashi

Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films Vol. 35 ( 1 ) page： 01A103 2016.11

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Papers - TSUTSUMI Takayoshi