研究者詳細 - 石川　健治

論文 - 石川　健治

分割表示 424 件中 221 - 240 件目／全件表示 >>

Pt nanoparticle-supported carbon nanowalls electrode with improved durability for fuel cell applications using C<sub>2</sub>F<sub>6</sub>/H<sub>2</sub> plasma-enhanced chemical vapor deposition 査読有り Open Access

Imai, S; Kondo, H; Hyungjun, C; Ishikawa, K; Tsutsumi, T; Sekine, M; Hiramatsu, M; Hori, M

APPLIED PHYSICS EXPRESS 12 巻 ( 1 ) 2019年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Applied Physics Express

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 C <inf>2</inf> F <inf>6</inf> /H <inf>2</inf> plasma-enhanced chemical vapor deposition system (C <inf>2</inf> F <inf>6</inf> -CNWs). Even after the extended start/stop-simulation tests of fuel cell Pt/C <inf>2</inf> F <inf>6</inf> -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/C <inf>2</inf> F <inf>6</inf> -CNWs, graphene crystallinity is essential to extend electrochemical durability by inhibiting corrosion during fuel cell operation.

DOI： 10.7567/1882-0786/aaf0ab

Batch Fabrication of Nano-Gap Electrode Array Using Photo-Patterning and Resist UV-Curing

Nguyen Hai Minh, Kumeuchi Mako, Kumagai Shinya, Ishikawa Kenji, Hori Masaru, Sasaki Minoru

IEEJ Transactions on Sensors and Micromachines 139 巻 ( 1 ) 頁： 27 - 28 2019年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：The Institute of Electrical Engineers of Japan

<p>A nano-gap electrode array is batch-fabricated based on photolithography. A high resolution is obtained by using an over-hanging resist cover on the under-etched metal film. The process includes two-time mask-patterning. The first photoresist is UV-cured, allowing second patterning without degrading the first pattern. A nano-gap width of 237±63 nm is obtained from a 704-electrode array with an yield of 97%.</p>

DOI： 10.1541/ieejsmas.139.27

Molecular mechanisms of non-thermal plasmainduced effects in cancer cells 査読有り Open Access

Tanaka, H; Mizuno, M; Ishikawa, K; Toyokuni, S; Kajiyama, H; Kikkawa, F; Hori, M

BIOLOGICAL CHEMISTRY 400 巻 ( 1 ) 頁： 87 - 91 2019年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Biological Chemistry

Plasma is the fourth state of matter with higher energy than gas; non-thermal plasma (NTP) is currently available. As NTP is useful in sterilization, promoting wound healing and cancer treatments, the molecular mechanisms of plasma-induced effects in living cells and microorganisms are of significant interest in plasma medicine with medical-engineering collaboration. Molecular mechanisms of plasma-induced effects in cancer cells will be described in this minireview. Both direct and indirect methods to treat cancer cells with NTP have been developed. NTP interacts directly with not only cancer cells but also the liquids surrounding cancer cells and the immune cells that target them. Reactive oxygen and nitrogen species play key roles in NTP-induced effects; however, other mechanisms have been suggested. The complex interactions between NTP, cells and liquids have been extensively studied. In the future, details regarding NTP-induced effects on gene regulatory networks, signaling networks, and metabolic networks will be elucidated.

DOI： 10.1515/hsz-2018-0199

Single-cell microscopic raman spectroscopy for rapid microbial detection 査読有り

Onoshima D., Uchida K., Yukawa H., Ishikawa K., Hori M., Baba Y.

23rd International Conference on Miniaturized Systems for Chemistry and Life Sciences Microtas 2019 頁： 1374 - 1375 2019年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：23rd International Conference on Miniaturized Systems for Chemistry and Life Sciences Microtas 2019

We present a study of microbial Raman spectroscopy towards optimal approach of rapid microbiological methods (RMMs). Raman spectra of single microorganism cells were measured and analyzed by data clustering to identify the microbial species without culturing for colony formation.

DOI： 10.1002/ppap.201900023

Effect of N<sub>2</sub>/H<sub>2</sub> plasma on GaN substrate cleaning for homoepitaxial GaN growth by radical-enhanced metalorganic chemical vapor deposition (REMOCVD) 査読有り Open Access

Amalraj, FW; Dhasiyan, AK; Lu, Y; Shimizu, N; Oda, O; Ishikawa, K; Kondo, H; Sekine, M; Ikarashi, N; Hori, M

AIP ADVANCES 8 巻 ( 11 ) 2018年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Aip Advances

We developed a new method of GaN growth using Radical-Enhanced Metalorganic Chemical Vapor Deposition (REMOCVD) technology by which Gallium Nitride (GaN) grows at low temperatures without ammonia gas. In this method, we investigated the effect of N<inf>2</inf>/H<inf>2</inf> plasma on the GaN substrate surface cleaning prior to the growth of homoepitaxial GaN. In-situ reflection high-energy electron diffraction (RHEED) and atomic force microscope (AFM) were used to investigate the surface morphology of the cleaned GaN substrates. The interface between GaN substrate and homoepitaxially grown GaN by REMOCVD was evaluated by transmission electron microscope and the crystal quality was evaluated by X-ray diffraction. The in-situ N<inf>2</inf>/H<inf>2</inf> plasma cleaning at 600 °C shows a smooth surface morphology with streak diffraction lines observed by RHEED. Since the homoepitaxial growth of GaN was performed at 800 °C, the cleaned GaN substrate temperature was ramped up from 600 °C to 800 °C with and without plasma exposure to compare the effect of plasma. Homoepitaxially grown GaN on GaN substrates whose temperature was ramped up with plasma exposure showed good crystal quality with no threading dislocations at the interface. It was found that N<inf>2</inf>/H<inf>2</inf> plasma plays a significant role in the GaN surface cleaning for good quality crystal growth.

DOI： 10.1063/1.5050819

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

Zhang, Y; Imamura, M; Ishikawa, K; Tsutsumi, T; Kondo, H; Sekine, M; Hori, M

JAPANESE JOURNAL OF APPLIED PHYSICS 57 巻 ( 10 ) 2018年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Japanese Journal of Applied Physics

To satisfy the requirement for mask materials in high-temperature plasma etching, a novolac-based polymer mask was evaluated during high-temperature Cl<inf>2</inf> plasma etching. Although the etch rate of 8 nm/min was rather high at a low temperature of 230 °C, it decreased with the increase in temperature. The aromatic ring structures were significantly modified by vacuum ultraviolet (VUV) and Cl radicals during the processes above 300 °C and transformed to a highly cross-linked amorphous carbon (a-C) layer at the surface confirmed from infrared and Raman spectra. The formation of this a-C layer improved the etching resistance of the polymer mask. On the other hand, surface roughness can also be improved after processes above 300 °C corresponding to the generation of the a-C layer. Therefore, this polymer mask is a promising candidate for high-temperature plasma etching with high etch resistance, and a smooth surface can be obtained during processes above 300 °C.

DOI： 10.7567/JJAP.57.106502

Elevated-temperature etching of gallium nitride (GaN) in dual-frequency capacitively coupled plasma of CH<sub>4</sub>/H<sub>2</sub> at 300-500 °C 査読有り

Kako, T; Liu, ZC; Ishikawa, K; Kondo, H; Oda, O; Sekine, M; Hori, M

VACUUM 156 巻頁： 219 - 223 2018年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Vacuum

Elevated-temperature etching with CH<inf>4</inf>/H<inf>2</inf> plasma chemistry at 300 °C improves damage-less optical properties of GaN, solving issues of degradation on near-band-edge photoluminescence intensity on plasma etching at lower temperatures than 300 °C. Damage-less etching properties in a smooth surface, high photoluminescence intensity, and substantial stoichiometric ratio of gallium and nitrogen were obtained when the CH<inf>4</inf>/H<inf>2</inf> chemistry with substrate temperatures at 300–500 °C.

DOI： 10.1016/j.vacuum.2018.07.040

Cytotoxic effects of plasma-irradiated fullerenol 査読有り

Kanno, D; Tanaka, H; Ishikawa, K; Hashizume, H; Hori, M

JOURNAL OF PHYSICS D-APPLIED PHYSICS 51 巻 ( 37 ) 2018年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Physics D Applied Physics

Fullerenol dissolved in water was irradiated with a non-equilibrium atmospheric pressure plasma. Plasma irradiation altered the fullerenol solution by introducing carbonyl groups, ether bonds, and intercalated nitrate anions. The resulting plasma-irradiated fullerenol (PF) was added in cell culture medium. PF-supplemented medium exhibited a cytotoxic effect on HeLa cells. Notably, HeLa cells cultured in the PF-added cell culture medium generated intracellular reactive oxygen and nitrogen species, such that the endocytosis of PF induced the apoptotic cell death. The cytotoxic effect inducing apoptosis was found in the PF-supplemented medium.

DOI： 10.1088/1361-6463/aad510

大気圧プラズマ処理による異種材料接合招待有り査読有り

近藤博基, 堤隆嘉, 石川健治, 関根誠, 堀勝

化学工学 82 巻 ( 9 ) 2018年9月

New hopes for plasma-based cancer treatment 査読有り Open Access

Hiromasa Tanaka, Masaaki Mizuno, Kenji Ishikawa, Shinya Toyokuni, Hiroaki Kajiyama, Fumitaka Kikkawa, and Masaru Hori

Plasma 1 巻 ( 1 ) 頁： 150 - 155 2018年9月

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

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

IEEE International Symposium on Semiconductor Manufacturing Conference Proceedings 2018-December 巻 2018年7月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE International Symposium on Semiconductor Manufacturing Conference Proceedings

Our developed non-contact method for measurement of temperature of silicon (Si) wafer by using autocorrelation-type fourier domain low coherence interferometer has advantageous in accuracy and rapid response. We demonstrate measurements in temperature for Si wafer at real-time during plasma process and in estimation of heat flux to the wafer from plasma, involving heats balanced plasma source and conductive loss in Si. The analysis indicated that other heat sources like the chamber parts with relatively high temperature impact on the duty ratio during the process with feedback control of the wafer teperture.

DOI： 10.1109/ISSM.2018.8651183

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

Liu, ZC; Ishikawa, K; Imamura, M; Tsutsumi, T; Kondo, H; Oda, O; Sekine, M; Hori, M

JAPANESE JOURNAL OF APPLIED PHYSICS 57 巻 ( 6 ) 2018年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Japanese Journal 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

Progress in nanoscale dry processes for fabrication of high-aspect-ratio features: How can we control critical dimension uniformity at the bottom? 査読有り国際共著 Open Access

Ishikawa, K; Karahashi, K; Ishijima, T; Cho, SI; Elliott, S; Hausmann, D; Mocuta, D; Wilson, A; Kinoshita, K

JAPANESE JOURNAL OF APPLIED PHYSICS 57 巻 ( 6 ) 2018年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Japanese Journal of Applied Physics

In this review, we discuss the progress of emerging dry processes for nanoscale fabrication of high-aspect-ratio features, including emerging design technology for manufacturability. Experts in the fields of plasma processing have contributed to addressing the increasingly challenging demands of nanoscale deposition and etching technologies for high-aspect-ratio features. The discussion of our atomic-scale understanding of physicochemical reactions involving ion bombardment and neutral transport presents the major challenges shared across the plasma science and technology community. Focus is placed on advances in fabrication technology that control surface reactions on three-dimensional features, as well as state-of-the-art techniques used in semiconductor manufacturing with a brief summary of future challenges.

DOI： 10.7567/JJAP.57.06JA01

Low-autofluorescence fluoropolymer membrane filters for cell filtration 査読有り Open Access

Kihara, N; Kuboyama, D; Onoshima, D; Ishikawa, K; Tanaka, H; Ozawa, N; Hase, T; Koguchi, R; Yukawa, H; Odaka, H; Hasegawa, Y; Baba, Y; Hori, M

JAPANESE JOURNAL OF APPLIED PHYSICS 57 巻 ( 6 ) 2018年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Japanese Journal of Applied Physics

A fluoropolymer membrane filter with through-holes was fabricated by photolithographic patterning and the dry etching method. 380,000 highly packed through-holes, each with a diameter of 7 µm were able to cover a whole area with a diameter of 13 mm. Ethylene tetrafluoroethylene (ETFE) was used as the membrane, which was suitable for the fluorescence detection of rare cells such as circulating tumor cells (CTCs) in human blood. The device fabrication for the size based capture of rare cells in blood such as CTCs is realized in this study.

DOI： 10.7567/JJAP.57.06JF03

Impact of helium pressure in arc plasma synthesis on crystallinity of single-walled carbon nanotubes 査読有り

Ando, A; Takeda, K; Ohta, T; Ito, M; Hiramatsu, M; Ishikawa, K; Kondo, H; Sekine, M; Suzuki, T; Inoue, S; Ando, Y; Hori, M

JAPANESE JOURNAL OF APPLIED PHYSICS 57 巻 ( 6 ) 2018年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Japanese Journal of Applied Physics

Single-walled carbon nanotubes (SWNTs) were synthesized with a high growth rate by an arc plasma method employing the electrodes made from a Ni–Y mixture catalyst. In a previous study, it was reported that the monitoring of high-crystallinity SWNT growth enabled the evaluation of the results of the optical emission spectroscopy (OES) of C<inf>2</inf>, Ni, and Y. Here, the impact of helium pressure of arc plasma on the high crystallinity of SWNTs was determined by considering the high intensity ratios of catalytic metals over C<inf>2</inf> emissions at low helium pressures in the arc plasma.

DOI： 10.7567/JJAP.57.06JF01

Effects of gas residence time of CH<sub>4</sub>/H<sub>2</sub> on sp<SUP>2</SUP> fraction of amorphous carbon films and dissociated methyl density during radical-injection plasma-enhanced chemical vapor deposition 査読有り

Sugiura, H; Jia, LY; Kondo, H; Ishikawa, K; Tsutsumi, T; Hayashi, T; Takeda, K; Sekine, M; Hori, M

JAPANESE JOURNAL OF APPLIED PHYSICS 57 巻 ( 6 ) 2018年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Japanese Journal of Applied Physics Part 1 Regular Papers and Short Notes and Review Papers

Quadruple mass spectrometric measurements of CH<inf>3</inf> density during radical-injection plasma-enhanced chemical vapor deposition to consider the sp<sup>2</sup> fraction of amorphous carbon (a-C) films were performed. The sp<sup>2</sup> fraction of the a-C films reached a minimum of 46%, where the CH<inf>3</inf> density was maximum for a residence time of 6 ms. The sp<sup>2</sup> fraction of the a-C films was tailored with the gaseous phase CH<inf>3</inf> 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

Dry Process FOREWORD 査読有り

Karahashi, K; Kinoshita, K; Higashi, S; Ishikawa, K; Ishijima, T; Kuboi, N

JAPANESE JOURNAL OF APPLIED PHYSICS 57 巻 ( 6 ) 2018年6月

Dissociative properties of 1,1,1,2-tetrafluoroethane obtained by computational chemistry 査読有り

Hayashi, T; Ishikawa, K; Sekine, M; Hori, M

JAPANESE JOURNAL OF APPLIED PHYSICS 57 巻 ( 6 ) 2018年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Japanese Journal of Applied Physics

The electronic properties and dissociative channels of the alternative to the CCl<inf>2</inf>F<inf>2</inf> (CFC-12) refrigerant, 1,1,1,2-tetrafluoroethane (HFC-134a) with a low global warming potential (GWP, 1430), were revealed by computational chemistry. The results show that CF<inf>3</inf><sup>+</sup> and CHF<inf>2</inf><sup>+</sup> ions are mainly produced by ionization. The CF<inf>3</inf>CH<inf>2</inf><sup>+</sup> ion is produced by ion pair formation and by direct ionization in the energy region higher than approximately 15 eV, but also in small amounts by the ionization of the dissociated CF<inf>3</inf>CH<inf>2</inf> radical. This information is useful for etching process engineers in leading-edge semiconductor manufacturing.

DOI： 10.7567/JJAP.57.06JC02

Nanographene synthesized in triple-phase plasmas as a highly durable support of catalysts for polymer electrolyte fuel cells 査読有り

Amano, T; Kondo, H; Takeda, K; Ishikawa, K; Hiramatsu, M; Sekine, M; Hori, M

JAPANESE JOURNAL OF APPLIED PHYSICS 57 巻 ( 4 ) 2018年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Japanese Journal of Applied Physics

Nanographene was synthesized in triple-phase plasmas comprising a gaseous phase, a gas-liquid boundary layer, and an in-liquid phase using a setup in which one electrode was placed in the gaseous phase while the other was immersed in the liquid phase. The triple-phase plasmas were generated using a pure alcohol, such as ethanol, 1-propanol, or 1-butanol, by applying a high voltage to a pair of electrodes made of copper or graphite. The nanographene synthesized using ethanol had high durability and thus could serve as a catalyst support in polymer electrolyte fuel cells (PEFCs). The PEFCs exhibited low degradation rates in the high-potential cycle test of a half-cell, as a result of which, a loss of only 10% was observed in the effective electrochemical surface area of Pt, even after 10,000 cycles.

DOI： 10.7567/JJAP.57.045101

Oxygen reduction reaction properties of nitrogen-incorporated nanographenes synthesized using in-liquid plasma from mixture of ethanol and iron phthalocyanine 査読有り

Amano, T; Kondo, H; Takeda, K; Ishikawa, K; Hiramatsu, M; Sekine, M; Hori, M

JAPANESE JOURNAL OF APPLIED PHYSICS 57 巻 ( 4 ) 2018年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Japanese Journal of Applied Physics

Nanographenes were synthesized using in-liquid plasma from a mixture of iron phthalocyanine and ethanol. In a previous study, micrometer-scale flakes with nitrogen incorporation were obtained. A nonprecious metal catalytic activity was observed with 3.13 electrons in an oxygen reduction reaction under an acidic solute condition. Large-surface-area, high-graphene-crystallinity, and iron-carbon-bonding sites were found owing to a high catalytic activity in Fe-N/nanographene.

DOI： 10.7567/JJAP.57.040303

　前のページ - 次のページ　

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22