研究者詳細 - 石川　健治

論文 - 石川　健治

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Biocompatibility of conformal silicon carbide on carbon nanowall scaffolds 査読有り Open Access

Ono, K; Koide, T; Ishikawa, K; Tanaka, H; Kondo, H; Sugawara-Narutaki, A; Jin, Y; Yasuhara, S; Hori, M; Takeuchi, W

JAPANESE JOURNAL OF APPLIED PHYSICS 62 巻 ( SA ) 2023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：Japanese Journal of Applied Physics

Silicon carbide (SiC) was coated onto carbon nanowall (CNW) scaffolds using chemical vapor deposition with a vinylsilane precursor at 700 °C to investigate the influence of the wall edge width, wall-to-wall distance, and surface morphology. The wall edge width ranged from 10 nm to those filling the wall-to-wall space without disrupting the CNW morphology. When SiC-coated CNWs (SiC/CNWs) were used as scaffolds for cell culture, cell viability increased until the edge area ratio reached 40%. In over 40% of edge area ratio, cell viability was saturate and comparable to flat surfaces such as SiC films on the Si substrate (SiC/Si) and control samples prepared using polystyrene. Calcification was suppressed in the CNWs, SiC/CNWs, and SiC/Si scaffolds compared to polystyrene. Our results suggest that SiC-coated CNW scaffolds could suppress calcification and promote cell proliferation.

DOI： 10.35848/1347-4065/ac9319

Web of Science

Scopus

Science-based, data-driven developments in plasma processing for material synthesis and device-integration technologies 査読有り国際共著国際誌 Open Access

Kambara, M; Kawaguchi, S; Lee, HJ; Ikuse, K; Hamaguchi, S; Ohmori, T; Ishikawa, K

JAPANESE JOURNAL OF APPLIED PHYSICS 62 巻 ( SA ) 頁： SA0803 2023年1月

担当区分：最終著者,　責任著者記述言語：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

Low-temperature plasma-processing technologies are essential for material synthesis and device fabrication. Not only the utilization but also the development of plasma-related products and services requires an understanding of the multiscale hierarchies of complex behaviors of plasma-related phenomena, including plasma generation in physics and chemistry, transport of energy and mass through the sheath region, and morphology- and geometry-dependent surface reactions. Low-temperature plasma science and technology play a pivotal role in the exploration of new applications and in the development and control of plasma-processing methods. Presently, science-based and data-driven approaches to control systems are progressing with the state-of-the-art deep learning, machine learning, and artificial intelligence. In this review, researchers in material science and plasma processing, review and discuss the requirements and challenges of research and development in these fields. In particular, the prediction of plasma parameters and the discovery of processing recipes are asserted by outlining the emerging science-based, data-driven approaches, which are called plasma informatics.

DOI： 10.35848/1347-4065/ac9189

Open Access

Web of Science

Scopus

Effects of High-Quality Carbon Nanowalls Ionization-Assisting Substrates on Surface-Assisted Laser Desorption/Ionization Mass Spectrometry Performance 査読有り Open Access

Sakai, R; Kondo, H; Ishikawa, K; Ohta, T; Hiramatsu, M; Tanaka, H; Hori, M

NANOMATERIALS 13 巻 ( 1 ) 2023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：Nanomaterials

Surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) is performed using carbon nanowalls (CNWs) for ionization-assisting substrates. The CNWs (referred to as high-quality CNWs) in the present study were grown using a radical-injection plasma-enhanced chemical vapor deposition (RI-PECVD) system with the addition of oxygen in a mixture of CH<inf>4</inf> and H<inf>2</inf> gases. High-quality CNWs were different with respect to crystallinity and C–OH groups, while showing similar wall-to-wall distances and a wettability comparable to CNWs (referred to as normal CNWs) grown without O<inf>2</inf>. The efficiency of SALDI was tested with both parameters of ion intensity and fragmental efficiency (survival yield (SY)) using N-benzylpyridinuim chloride (N-BP-CI). At a laser fluence of 4 mJ/cm2, normal CNWs had an SY of 0.97 and an ion intensity of 0.13, while 5-sccm-O<inf>2</inf>– high-quality CNWs had an SY of 0.89 and an ion intensity of 2.55. As a result, the sensitivity for the detection of low-molecular-weight analytes was improved with the high-quality CNWs compared to the normal CNWs, while an SY of 0.89 was maintained at a low laser fluence of 4 mJ/cm2. SALDI-MS measurements available with the high-quality CNWs ionization-assisting substrate provided high ionization and SY values.

DOI： 10.3390/nano13010063

Selective isotropic atomic-layer etching of thin films by using dry chemical removal tool 査読有り

Shinoda K., Miyoshi N., Kobayashi H., Izawa M., Ishikawa K., Hori M.

Proceedings of SPIE the International Society for Optical Engineering 12499 巻 2023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：Proceedings of SPIE the International Society for Optical Engineering

There has been considerable interest in the development of isotropic atomic layer etching (ALE) for the conformal removal of thin films. Material selectivity is crucial for the development of isotropic ALE because the next generation of semiconductor devices will be constructed with miniaturized 3D structures using a variety of very thin films. We developed plasma-assisted thermal-cyclic ALE, which is a repetition of surface modification by plasma exposure and removal of the modified surface by infrared heating. We developed a 300-mm tool, namely, dry chemical removal (DCR), which is equipped with an inductively coupled plasma (ICP) source and infrared lamps, to facilitate rapid thermal desorption of the modified surface. An important feature of the plasma-assisted thermal-cyclic ALE is that it has more tuning knobs than that of conventional ALE because it uses two temperatures: a low temperature for surface modification and an elevated temperature for the removal of the modified surface. This paper presents the selective ALE of various materials, i.e., Si3N4, TiN, W, and SiGe using the developed tool. The mechanisms of the selectivity are divided into two categories: formation of an ammonium salt-based modified layer and selectivity control by adjusting the infrared heating time. This paper reviews the selective ALE mechanisms, focusing on the results of in situ analysis of surface reactions, and presents some of the latest findings.

DOI： 10.1117/12.2664547

Scopus

低温大気圧プラズマによるフリーラジカル生成とその生物学的意義-放射線との比較- 査読有り

近藤隆, 田中宏昌, 石川健治, 堀勝

化学工業 74 巻 ( 2 ) 頁： 120 - 126 2023年

総説：プラズマなどで処理された水の多様性査読有り

石川健治

静電気学会誌 46 巻頁： 209 2023年

C2F4の電子物性とPTFEの生成機構査読有り

林俊雄, 石川健治, 関根誠, 堀勝, 兒玉直人, 豊田浩孝

応用物理学会学術講演会講演予稿集 2023.1 巻 ( 0 ) 頁： 1235 2023年

F2添加 Ar プラズマを用いた基板昇温下での AlGaN の原子層エッチング査読有り

中村昭平, 谷出敦, 灘原壮一, 石川健治, 小田修, 堀勝

応用物理学会学術講演会講演予稿集 2023.1 巻 ( 0 ) 頁： 1228 2023年

パネルディスカッション査読有り

石川健治, 浜口智志, 成田絵美, 白谷正治, 冨谷茂隆, 室賀駿, 佐藤孝紀, 野崎智洋, 吉田朋子

応用物理学会学術講演会講演予稿集 2023.1 巻 ( 0 ) 頁： 3293 2023年

非平衡大気圧プラズマがゼブラフィッシュに及ぼす影響とその機構解明査読有り

紅林佑弥, 石川健治, 田中宏昌, 秋山真一, 橋爪博司, 堀勝

応用物理学会学術講演会講演予稿集 2023.1 巻 ( 0 ) 頁： 1260 2023年

Impact of microsecond-pulsed plasma-activated water on papaya seed germination and seedling growth 査読有り

Xi, DK; Zhang, XH; Yang, SZ; Yap, SS; Ishikawa, K; Hori, M; Yap, SL

CHINESE PHYSICS B 31 巻 ( 12 ) 2022年12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：Chinese Physics B

The seed of Carica papaya consists of a hard shell-like testa with inhibitors in vivo causing slow, erratic and asynchronous germination. In this work, plasma-activated water prepared by microsecond-pulsed plasma jets (μPAW) was applied to treat papaya seeds. The μPAW after plasma activation of 30 min was about 40 °C. The reactive species such as NO<inf>2</inf>, NO<inf>3</inf>, and H<inf>2</inf>O<inf>2</inf> in the μPAW activated from deionized water were measured and correlated to the seed germination rate and the seedling growth performance. The μPAW-treated papaya seed achieved a higher germination rate of 90%, which is 26% higher than the control group using deionized water. Comparing the results with a hot water (40 °C) reference group showed that the reactive species in μPAW played primary roles in germination improvement, with little effect caused by the heat shock. The μPAW also sterilized the treated seeds, reducing the germination stress. The morphological change in the seeds was observed by SEM, showing an effect of physical etching after treatment promoting seed imbibition. The biochemical mechanism of the seed germination was deduced with reference to the evolution of surface chemistry, functional groups, and ABA content. The accelerated seed metabolism observed was corresponded to the chemical modification pathway. Besides, early seedlings developed from treated seeds were observed to be healthy, grow more leaves, and have better root structures. The content of MDA in the treated papaya seedlings decreased along with increased SOD and higher ion concentration. The μPAW that can be prepared at atmospheric pressure for bulk production offers a low-risk and cost-effective seed priming technology that may significantly increase the production of agricultural crops.

DOI： 10.1088/1674-1056/ac904e

Web of Science

Scopus

Indoor Floor Heel Mark Removal Using Spark Discharges and Pressurized Airflow 査読有り Open Access

Sakamoto, Y; Tsutsumi, T; Tanaka, H; Ishikawa, K; Hashizume, H; Hori, M

COATINGS 12 巻 ( 12 ) 2022年12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：Coatings

Heel marks (HMs), which are the black stains made by shoe soles on indoor floors, can be difficult to remove. However, this study shows how spark discharges combined with pressurized airflow in 60 s discharge treatments can remove such HMs. We further show that maximizing the HM removal rates depended on the electrode gap distance because of changes in the spark discharge parameters. In our experiments, the electrical voltage waveforms are shown with voltage spikes, called spark discharges, and the spike numbers were counted in 0.6-ms time units. It was found that the number of spark discharges increases when the electrode gap distance was widened from 5 mm to 10 mm and the pressurized airflow was added, and the HM removal rates increased 11.5%, the HM removal rates could be maximized. Taken together, the results show that spark discharges combined with pressurized air can remove HMs from indoor floors without no visual damage. This paper is a preliminary report showing that HMs can be removed by plasma.

DOI： 10.3390/coatings12121938

Open Access

Web of Science

Scopus

Carbon Layer Formation on Hexagonal Boron Nitride by Plasma Processing in Hydroquinone Aqueous Solution 査読有り

Inoue, K; Sakakibara, N; Goto, T; Ito, T; Shimizu, Y; Hakuta, Y; Ishikawa, K; Hori, M; Terashima, K

ACS APPLIED MATERIALS & INTERFACES 14 巻 ( 47 ) 頁： 53413 - 53420 2022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：ACS Applied Materials and Interfaces

Although hexagonal boron nitride (hBN) is a thermally conductive and electrically insulating filler in composite materials, surface modification remains difficult, which limits its dispersibility and functionalization. In this study, carbon layer formation on hBN particles by plasma processing in hydroquinone aqueous solution was investigated as a surface modification technique. Carbon components with features of polymeric hydrogenated amorphous carbon were found to be uniformly distributed on the hydroquinone-aided plasma-modified hBN (HQpBN) particles. Electron spin resonance measurements revealed abundant unpaired electrons in HQpBN, indicating that defects were formed on hBN by plasma processing and that the carbon layer contained dangling bonds. The defects on hBN could help in the attachment of the carbon layer, whereas the dangling bonds could act as reactive sites for further functionalization. The carbon layer on HQpBN was successfully functionalized with isocyanate groups, thus confirming the ability of this carbon layer to facilitate surface modification. These results demonstrate that the carbon layer formed on hBN can provide a designable interface in organic/inorganic composite materials.

DOI： 10.1021/acsami.2c15951

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PubMed

Dry etching of ternary metal carbide TiAlC via surface modification using floating wire-assisted vapor plasma 査読有り Open Access

Nguyen, TTN; Shinoda, K; Hamamura, H; Maeda, K; Yokogawa, K; Izawa, M; Ishikawa, K; Hori, M

SCIENTIFIC REPORTS 12 巻 ( 1 ) 頁： 20394 2022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：Scientific Reports

Dry etching of ternary metal carbides TiAlC has been first developed by transferring from wet etching to dry etching using a floating wire (FW)-assisted Ar/ammonium hydroxide vapor plasma. FW-assisted non-halogen vapor plasma generated at medium pressure can produce high-density reactive radicals (NH, H, and OH) for TiAlC surface modifications such as hydrogenation and methylamination. A proposed mechanism for dry etching of TiAlC is considered with the formation of the volatile products from the modified layer.

DOI： 10.1038/s41598-022-24949-1

Effects of deposition precursors of hydrogenated amorphous carbon films on the plasma etching resistance based on mass spectrometer measurements and machine learning analysis 査読有り Open Access

Kurokawa, J; Kondo, H; Tsutsumi, T; Ishikawa, K; Sekine, M; Hori, M

VACUUM 205 巻 2022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：Vacuum

In the growth of hydrogenated amorphous carbon (a-C:H) films by plasma enhanced chemical vapor deposition (PECVD) with H<inf>2</inf>, CH<inf>4</inf> and C<inf>3</inf>H<inf>6</inf> plasma, the gas phase reaction of active species and their contribution to properties of deposited a-C:H film were quantitatively investigated using appearance quadrupole mass spectrometry (QMS) and machine learning. The QMS measurement indicated that two-types of neutral radicals were generated by the dissociation and polymerization of the raw material gasses. A random forest regression model was employed as a prediction model to analyze the correlation between the neutral species and etching rates by molecular oxygen (O<inf>2</inf>) plasma without any stage bias, which were measured by in-situ ellipsometry. The coefficient of determination (R2), an indicator of the degree of prediction accuracy, was 0.906 and 0.584 for the training and test data, respectively. SHapley Additive exPlanations (SHAP), interpreting the random forest model, were used to quantitatively indicate the contribution of radicals to the etching rate, including their synergistic and secondary effects. They indicated that carbon-rich radicals, such as C<inf>3</inf>H<inf>3</inf> and C<inf>5</inf>H<inf>5</inf>, contributed to a decrease in the etching rate, whereas hydrogen-rich radicals, such as CH<inf>x</inf> (x=1,2,3,4), C<inf>2</inf>H<inf>5</inf>, C<inf>4</inf>H<inf>9</inf>, and C<inf>5</inf>H<inf>9,11</inf> induced an increase in the etching rate by the O<inf>2</inf> plasma. (200 words)

DOI： 10.1016/j.vacuum.2022.111351

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Dissociation channels of c-C4F8 to C2F4 in reactive plasma 査読有り国際誌

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

JAPANESE JOURNAL OF APPLIED PHYSICS 61 巻 ( 10 ) 頁： 106006 2022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

Progress in computational methods and personal computing has made possible more accurate estimations for primary dissociation channels and energies. The main dissociation route is revealed to be via the 7E excited state with an energy of 12.23 eV, which is composed of transitions from the highest occupied molecular orbital with b1 symmetry to some degenerate unoccupied e molecular orbitals. The main contributing e orbitals consisted of antibonding combination of C2F4 π-bonding orbitals. This degenerate 7E state is lowered by non-adiabatic transitions through the conical interactions on the dissociating route to 2C2F4, so the energy is finally relaxed at the dissociative second lowest 1E excited state leading to 2C2F4 production. In the electron attachment process, the calculated results show that the F- ion is produced from the excited states of the D4h c-C4F8- ion through conical interactions at the energies of 4.3 eV, 5.6 eV, and 5.0 eV, along the C-F dissociation route.

DOI： 10.35848/1347-4065/ac895e

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Scopus

非平衡大気圧プラズマを用いた陸上養殖実現に向けた基礎的研究査読有り Open Access

田中宏昌, 秋山真一, 橋爪博司, 紅林佑弥, 石川健治, 堀勝

応用物理学会学術講演会講演予稿集 2022.2 巻 ( 0 ) 頁： 1741 - 1741 2022年8月

In-liquid plasma synthesis of iron-nitrogen-doped carbon nanoflakes with high catalytic activity 査読有り

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

PLASMA PROCESSES AND POLYMERS 19 巻 ( 8 ) 2022年8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：Plasma Processes and Polymers

Flake-shaped carbon nanomaterials with nitrogen (N) and iron (Fe) addition, so-called carbon nanoflakes (CNFLs), were synthesized by the in-liquid plasma using two different kinds of additive agents, such as hemin and iron (II) phthalocyanine (FePc). According to scanning electron microscopy images and Raman spectra, CNFLs with a size of at least 100 nm order were formed regardless of types of additive agents, and crystallinity of six-membered ring structures was improved as additive agents increased. Photoelectron spectra showed that pyridinic N contents increased from 1.05% to 2.02% with increasing FePc, while those decreased from 0.34% to 0.14% with hemin. In the oxygen reduction reaction, onset potential values also increased from 0.71 to 0.79 eV with increasing FePc, while those decreased from 0.60 to 0.47 eV with hemin. These results suggested that the catalytic activity of CNFLs was effectively improved by the increase of pyridinic N by the in-liquid plasma synthesis with FePc. In contrast, the electron transfer numbers reached 3.81 when hemin increased, although those were less than 2.88 in the cases using FePc. These results mean that the in-liquid plasma synthesis method of CNFLs using FePc has the potential to further improve its catalytic activity.

DOI： 10.1002/ppap.202100203

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Dry Process

Akatsuka H., Kurihara K., Toyoda H., Karahashi K., Ishikawa K., Ichiki T., Eriguchi K., Kuboi N., Matsui M., Nunomura S.

Japanese Journal of Applied Physics 61 巻 ( SI ) 2022年7月

Study of optical emission spectroscopy using modified Boltzmann plot in dual-frequency synchronized pulsed capacitively coupled discharges with DC bias at low-pressure in Ar/O2/C4F8 plasma etching process 査読有り

Sahu, BB; Nakane, K; Ishikawa, K; Sekine, M; Tsutsumi, T; Gohira, T; Ohya, Y; Ohno, N; Hori, M

PHYSICAL CHEMISTRY CHEMICAL PHYSICS 24 巻 ( 22 ) 頁： 13883 - 13896 2022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：Physical Chemistry Chemical Physics

We consider the corona model and local thermal equilibrium approximations of a real plasma to measure the electron temperature (T<inf>e</inf>) and density (n<inf>e</inf>), respectively, using the optical emission spectroscopy (OES) method in dual-frequency pulsed capacitively coupled plasmas (CCPs) in a reactive mixture of Ar/O<inf>2</inf>/C<inf>4</inf>F<inf>8</inf> at a low operating pressure. The operation conditions such as DC continuous and synchronized were used for the study and plasma characterization for the intended plasma application such as high aspect ratio etching (HARE). We show that the present plasma conditions are dominated by a corona balance rather than the supremacy of multi-step excitation. This fact has enabled us to utilize the modified Boltzmann plot technique to evaluate the T<inf>e</inf> values. In the second method, we simultaneously used the Boltzmann and Saha equations to determine the n<inf>e</inf> value using the line intensity ratio and the value of T<inf>e</inf>. Time-resolved measurements of T<inf>e</inf> and n<inf>e</inf> were performed for completeness, and the insight of the pulsed discharge was investigated. Time evolution of n<inf>e</inf> and T<inf>e</inf> using the OES method revealed a similar trend in the change of plasma parameters, indicating electron impact ionization during the pulse on phase. It was seen that n<inf>e</inf> in the afterglow speedily decreased within a short time of ∼5 μs. Analysis suggests the formation of afterglow plasmas, which are composed of positive and negative ions with very low electron density. The results revealed that the DC-synchronized operation could be useful for plasma application such as HARE due to different plasma characteristics. It also suggests the production of ion-ion plasmas by the effective utilization of negative ions in the afterglow phase. The corona balance condition was validated in our experiments, and the results were compared with the existing literature.

DOI： 10.1039/d2cp00289b

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論文 - 石川 健治

<石川　健治>

論文 - 石川　健治