Tomoji Ohishi

Tomoji Ohishi
Shibaura Institute of Technology · Department of Applied Chemistry

About

139
Publications
5,116
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1,417
Citations
Citations since 2016
40 Research Items
337 Citations
20162017201820192020202120220102030405060
20162017201820192020202120220102030405060
20162017201820192020202120220102030405060
20162017201820192020202120220102030405060

Publications

Publications (139)
Article
Metal printing technique has attracted attention as a promising manufacturing method. To date, Cu patterning with high electroconductivity has been achieved by laser-reduced thermochemical precipitation in air using glyoxylic acid Cu complexes. However, it is difficult to fabricate thick Cu patterns due to their large volume shrinkage. In this stud...
Article
Objectives: Both pancreatic stenting and rectal nonsteroidal anti-inflammatory drugs (NSAIDs) prevent post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis. The aim of the study was to compare post-ERCP pancreatitis (PEP) prophylaxis using pancreatic stents and/or rectal NSAIDs prospectively. Methods: A total of 321 patients un...
Article
Full-text available
This work focuses on a carbon-based imprinted polymer composite, employed as a molecular recognition and sensing interface in fabricating a disposable electrochemical sensor. The carbon paste electrode was made of a molecularly imprinted polymer comprising a copolymer of methacrylic acid as the functional monomer and blended crosslinking monomers o...
Article
Co patterns were fabricated by using femtosecond laser pulse-induced thermochemical reduction of glyoxylic acid Co complex. Glyoxylic acid Co complex was synthesized by mixing CoSO4·7H2O and glyoxylic acid, following that the complex was dissolved in 2-aminoethanol/ethanol. Femtosecond laser pulses were focused and irradiated to the glyoxylic acid...
Article
This paper presents the direct writing of thermoelectric couples composed of Cu–Ni alloy in ambient atmosphere. Patterns of Cu, Ni, and Cu–Ni alloys were directly written by the rapid heating and reduction of glyoxylic acid metal (Cu, Ni, and Cu/Ni mixed) complexes on glass substrates using femtosecond laser pulses without significant oxidation. Th...
Article
Introduction Molecularly imprinted polymers (MIPs) are recognition elements with specific cavities designed for a particular target molecule. Recently, MIPs have been used in various applications explicitly requiring molecular recognition. In MIPs, the crosslinking monomers and functional monomers, having an affinity with a target molecule, are cop...
Article
Full-text available
We investigate the direct writing properties of copper (Cu) patterns on glass and polydimethylsiloxane (PDMS) substrates using femtosecond laser pulse-induced thermochemical reduction of glyoxylic acid copper (GACu) complex. The films of the GACu complex coated on the substrates were irradiated by focused femtosecond laser pulses using a low numeri...
Article
1. Introduction The resistive random access memory (ReRAM), which is a nonvolatile memory device, on flexible plastic substrate have been widely investigated for future wearable device. The flexible ReRAM based on metal-insulator-metal (MIM) structure is generally fabricated at relatively low temperature (~250°C) from the viewpoint of heat resistan...
Article
Introduction Titanium dioxide (TiO 2 ) has been widely investigated as a channel layer for oxide thin film transistors (oxide-TFTs) and an active layer of resistive random access memory [1]. TiO 2 is a very attractive because high dilectric constant (k) of anatase and rutile phases are ~30 and ~80, respectively, and easily converted from an insula...
Article
Full-text available
We have fabricated Cu-based micropatterns in an ambient environment using femtosecond laser direct writing to reduce a glyoxylic acid Cu complex spin-coated onto a glass substrate. To do this, we scanned a train of focused femtosecond laser pulses over the complex film in air, following which the non-irradiated complex was removed by rinsing the su...
Article
A solution of polysilazane (Perhydropolysilazane) was applied to a heat resistant PET substrate, and then irradiated with excimer light at 150 °C to form a gas barrier film. This film primarily consisted of a thin layer of SiO 2 , and had very high gas barrier properties, with a water vapor transmission rate of 0.02 g/m ² ·day or less (40 °C/90% RH...
Article
This work investigated characteristics of Al 2 O 3 /native oxide/n-GaN MOS capacitors by post-metallization annealing (PMA). A native oxide interlayer which composed of ϵ- and γ-Ga 2 O 3 phases (Native oxide) and the reduced amount of one (Reduced) on n-GaN were prepared by cleaning only a sulfuric acid peroxide mixture (SPM) and both SPM and buffe...
Article
Characteristics of hafnium silicate as gate dielectric in n-GaN capacitors were investigated. The Hf0.57Si0.43O x , Hf0.64Si0.36O x and HfO2 films exhibited high dielectric constants of 15.4, 15.9, and 17.6, respectively. The Hf0.57Si0.43O x and Hf0.64Si0.36O x films, which had an amorphous structure, showed superior properties, including a minimal...
Article
Preparation and photo-patterning characteristics of organic-inorganic hybrid thin film containing latent pigments by photo-acid-generator (PAG) and microwave irradiation have been investigated. The acrylic thin film modified with methoxysilane containing PAG and latent pigments was formed on glass or PET film, and then was irradiated with ultraviol...
Article
Full-text available
We have investigated characteristics of Al2O3 thin films, which are deposited by plasma-enhanced atomic layer deposition (PE-ALD) and thermal ALD (TH-ALD) with oxygen plasma and H2O as oxidant gas, respectively, and Al(CH3)3 precursor. The Al2O3 film, which was deposited at 50℃, exhibited a large leakage current property. The positive (~10¹⁸ cm-3)...
Article
Cu micropatterns were directly written on glass substrates using reduction of glyoxylic acid Cu complex induced by femtosecond laser pulses. We investigated the patterning properties at various laser irradiation conditions. Although the lower resistivity was obtained at 0.312-0.468 nJ, the resistivity increased at lower and higher pulse energies. X...
Article
Ruthenium oxide (RuO2) thin films, which are deposited by plasma-enhanced atomic layer deposition (PE-ALD) with a Ru(EtCp)2 precursor and oxygen plasma, exhibit a smoother surface [root mean square (RMS) roughness <1 nm] on ionic Al2O3 and TiO2 buffer layers than on a covalent SiO2 buffer layer (RMS roughness of RuO2: 2.5 nm). The Al2O3 and TiO2 bu...
Article
Full-text available
The effects of excimer light irradiation on polysilazane coatings formed on PET films with vacuum-evaporated SiO2 coatings and the effects of these coatings on gas barrier characteristics have been investigated. The temperature during light irradiation has a large effect on the coating’s molecular structure and gas barrier characteristics. When irr...
Article
We studied characteristic of carbon-doped indium-tungsten-oxide (In1-xWxOC) thin film transistors (TFTs) with SiO2 gate insulator. The In1-xWxOC films, were fabricated by co-sputtering method with WC and In2O3 targets, had an amorphous structure and maintained W-C bond even after annealing at 300 °C. The saturation field-effect mobility, on/off cur...
Article
Introduction InO x -based thin film transistors (TFTs) such as In-Ga-Zn-O, In-Ti-O, In-W-O, and In-Si-O have been widely investigated. We also reported carbon doped In-Si-O (In 1-x Si x OC) as channel material because of the highest bond dissociation energy of 1076 kJ/mol between carbon and oxygen. The turn on voltage shift (Δ V on ) of In 0.80 Si...
Article
Ruthenium doped indium oxide (In1−xRuxOy) films fabricated using DC magnetron co-sputtering with In2O3 and Ru targets were investigated for use as transparent conductive oxides. The In1−xRuxOy films had an amorphous structure in the wide compositional range of x = 0.3–0.8 and had an extremely smooth surface. The transmittance and resistivity of the...
Article
Full-text available
Transmittance and reflectance spectra of the polysilazane film formed on the PET film are shown in Figure 4. The PET film shows transmittance of about 90% (i.e., almost no absorption) in the wavelength range from 380 to 800 nm. It is clear from the figure that when the polysilazane film is formed on the PET film, as the photo-irradiation temperatur...
Article
Introduction Recently, thin-film transistor (TFT) with InO x -based metal oxide semiconductors such as Ga-In-Zn-O (GIZO) [1], In-Ga-O [2], In-Sn-O [3, 4], and In-Zn-O [5, 6] have attracted attention as high-speed switches for next-generation flat-panel display. However it remains a big issue of the anomalous oxygen vacancies (V O ) formation, which...
Article
Full-text available
A new flexible substrate for flexible electronics has been developed. The developed substrate consists of an ultra thin glass and TAC (triacethyl cellulose) film. An ultra thin glass and TAC film were joined with TEOS-DAC (TEOS: tetraethyl orthosilicate, DAC: diacethy cellulose) adhesive resin synthesized by sol-gel method by means of thermo-compre...
Article
In this paper, the authors studied anatase TiO2 films, fabricated by using atomic layer deposition and postdeposition annealing (PDA). The as-grown TiO2 films were of high purity; the carbon and nitrogen contents were within the x-ray photoelectron spectroscopy detection limit of 3–5 at. %. The anatase TiO2 film fabricated by PDA at 500 °C in O2 ha...
Conference Paper
http://ap-s.ei.tuat.ac.jp/isapx/2012/pdf/3A2-3.pdf The MIMO OTA (over the air) measurement systems, emulate the propagation environment in premises, are actively discussed. The propagation environment emulated by the MIMO OTA system is usually easy to re-produce and can precisely compare the performance of different antenna configurations or termin...
Conference Paper
http://ap-s.ei.tuat.ac.jp/isapx/2012/pdf/2A1-3.pdf The spread of small mobile terminals, such as cell phones, is spurring interest in Wireless Body Area Network (WBAN), including intrabody communication utilizing electromagnetic field on human body surface. In order to generate or detect the change in the EM field on human body surface, intrabody c...
Article
We investigate Vfb behavior of (TaC)(1-x)Al-x gated HfO2 MOS capacitors as a function of post metal annealing (PMA) temperature. The positive Vfb shift appears in PMA temperature at above 700 degrees C, while the negative Vfb shift occurs at below 600 degrees C. At below 600 degrees C, the effective work function (phi(m),(eff)) of gate electrode be...
Article
We investigated flatband voltage (Vfb) behavior for several Hf-based high-k dielectrics, including HfO2, Mg-, and La-incorporated HfO2, HfSiOx, and Mg-, La-, and N-incorporated HfSiOx, during the reduction (forming gas annealing: FGA) and oxidation annealing (ODA) processes. A negative Vfb shift appeared in all high-k dielectrics as the FGA tempera...
Article
Full-text available
The synthesis of Ph-SiO2 film containing Qn-BOC latent pigment using the sol-gel method and the formation of thin film using laser irradiation have been investigated. The film is useful for a wavelength selective absorption film for displays and optical disk. Newly developed film formation technique using latent pigment and laser irradiation gives...
Article
Various OTA (over-the-air) measurement systems have been proposed and discussed for the evaluation of MIMO wireless communication devices. The spatial channel emulators, which is a typical MIMO OTA measurement method, usually assume only the horizontal angle spread of multipath radio propagation channel. In this report, the effect of vertical angle...
Article
Full-text available
Remarkable progress in the physical parameters of net-current free plasmas has been made in the Large Helical Device (LHD) since the last Fusion Energy Conference in Chengdu, 2006 (O.Motojima et al., Nucl. Fusion 47 (2007) S668). The beta value reached 5 % and a high beta state beyond 4.5% from the diamagnetic measurement has been maintained for lo...
Article
A continuous synthesis technique to produce carbon nanoclusters such as multi-walled carbon nanotubes (MWCNTs) or carbon nanofibers (CNFs) is studied by using a well-controlled plasma jet. In this method, numerous fiber-like structures can be produced. Production of carbon nanoclusters are well enhanced by additionally injecting Ni powders compared...
Article
Effective work function (ϕm,eff) values of Hfx Ru1−x alloy gate electrodes on SiO2 metal-oxide-semiconductor (MOS) capacitors were carefully examined to assess whether the ϕm,eff was determined by the crystalline structure or the composition of the HfxRu1−x alloy. X-ray diffraction results indicated that the crystalline structures of HfxRu1−x alloy...
Article
Effect of ultrasound sonication was examined on the electroplating of iridium in aqueous hexabromoiridate(III) solution. The electrodeposits were evaluated by observing the defects of the iridium deposits by means of voltammetry, in which the current-potential curves of the iridium deposits on copper were measured. Applying ultrasound sonication to...
Article
Several origins for VFB shift have so far been discussed about metal/high-k/SiO2/Si structures and we focus on three topics such as bottom interface dipole at the high-k/interfacial layer (IL)-SiO2 interface, charge or dipole of bottom reaction layer in IL-SiO2, and dipole due to oxygen vacancy (Vo) in high-k layer by separating each type of these...
Article
The electroplating of iridium with cobalt from an electrolyte containing 26 mmol dm?3 sodium hexabromoiridate(III) and 85 mmol dm?3 cobalt(II) sulphate was examined. The codeposition of cobalt with iridium was observed in the electrolyte containing iridium ion at more positive potential than the deposition potential of cobalt alone. The composition...
Article
The effect of some alcohols as additives on the electroplating of iridium in an electrolyte composed of 52 mmol dm?3 sodium hexabromoiridate(III), 0?5 mol dm?3 sodium bromide and 0?5 mol dm?3 sodium sulphate was examined. The addition of alcohols such as 1-butanol, 2-butanol, ethylene glycol and glycerol could significantly keep the current efficie...
Article
The microstructural properties of the β-FeSi2/FeSi structure prepared from a molten salt have been characterized using transmission electron microscopy (TEM). The β-FeSi2 films were grown on FeSi substrates at the heat treatment temperature of 900 °C from 1 min to 24 h using the molten salt technique. It is found that the films consisted of a thin...
Article
Large-sized β-FeSi2 substrates were successfully prepared for the first time from the silicide bulk crystal grown by the molten salt method. The structural, electrical and optical properties of the as-grown β-FeSi2 bulk crystals were also investigated. The crystal is single phase β-FeSi2, and polycrystalline with no preferable growth crystallograph...
Article
Effective work function (φm,eff) values of Ru gate electrode on SiO2 and HfO2 MOS capacitors were carefully examined and discussed from the viewpoint of an effect of oxygen incorporation in Ru gate electrode on φm,eff. Annealing at 400°C in the reduction (3%H2) and the oxidation (1%O2) ambient resulted in similar changes in the φm,eff of Ru/HfO2/Si...
Article
Mg2Si1−xGex layers were grown on silicon–germanium substrates by heat treatment of the substrates in Mg vapor. The layers were grown by an interdiffusion process between the deposited Mg atoms and the substrates. It has been demonstrated that smooth and continuous layers can be grown with an abrupt layer/substrate interface, and no Kirkendall void...
Article
Single phase Sr2Si layers were successfully grown on Mg2Si/Si substrates for the first time. The Sr2Si layers are formed by an interdiffusion process between the deposited Sr atoms and Mg2Si/Si substrates. It has been confirmed that the formation of the SrSi and SrSi2 phases was suppressed when the layers were grown on Mg2Si/Si substrates. On the o...
Article
An edge transport barrier (ETB) similar to the tokamak H-mode has been observed for beam-heated plasma with two co-injected Neutral Beam Injectors (NBIs) in CHS. The Halpha emission showed a clear spontaneous drop followed by an increase of line-averaged electron density at the L-H transition. Stored energy increased by ˜ 40% with H-factor improvem...
Conference Paper
A 0.13μm magnetoresistive random access memory (MRAM) with 0.26×0.44μm<sup>2</sup> magnetic-tunneling-junction (MTJ) is presented for 1.2V high-speed operation beyond 143MHz, where MTJ parameters are best-tuned for its maximum performance. We have found that there is a universal relationship between magneto-resistance (MR) and resistance-area produ...
Article
A thin film containing rhodamine B derivative with ethoxy silano group was formed on organic film substrate using the sol–gel method. Rhodamine B derivative with a triethoxysilano group, SiO2 sol and acrylic polymer having a triethoxy group were reacted in alcohol to give a coating solution for film formation, followed to be roll-coated on polyethy...
Article
Semiconducting silicides, such as Mg2Si, β-FeSi2, Ca2Si, MnSi1.7 and Mn(Fe)Si1.7, were grown and their structural and morphological properties have been characterized. The layers were grown by interdiffusion process between deposited atoms and substrates. When the appropriate substrates and deposition species are used, the silicides can be easily g...
Article
β-FeSi2 layers have been successfully grown using a molten salt method for the first time. It was found that single phase and homogeneous β-FeSi2 layers with a columnar domain structure can be grown on FeSi substrates. The layer thickness was demonstrated to be controllable by the growth temperature and time, and was diffusion controlled. It was sh...
Article
With the objective of developing films for advanced systems, a photo-assisted sol–gel method has been used to form an anti-reflection/anti-static thin film on an organic film (PET) that has no heat-resistance, and the properties of the film have been evaluated. This method makes it possible to form a layered ITO/SiO2 structure on the film at 60 °C,...
Article
A rhodamine B derivative with ethoxy-silano group was prepared by reacting rhodamine B sulfonyl chloride with aminopropyltriethoxysilane in dry pyridine. This new rhodamine B derivative reacts with an SiO2 sol to connect directly with the silica matrix network. A wavelength-selective absorption film for display devices was prepared by using an SiO2...
Article
With the aim of developing a high-performance gas barrier material, a polysilazane film was applied to an indium tin oxide (ITO)-coated organic PET substrate (i.e., the ITO and polysilazane films were formed sequentially on the PET substrate), and its properties were evaluated. The resulting material exhibits favorable gas barrier characteristics (...
Article
A silicon alkoxide–water–ethanol mixed solution was irradiated with ultraviolet rays, and the change of the silicon alkoxide molecular structure was evaluated by 29Si nuclear magnetic resonance and Fourier transform infrared spectroscopies. Silicon alkoxide was hydrolyzed and the Si–OH bonds were produced by UV irradiation without any chemical cata...
Conference Paper
This paper proposes a new algorithm PPI (pen-position/penpressure/pen-inclination) for on-line pen input signature verification. The algorithm considers writer’s signature as a trajectory of pen-position, penpressure and pen-inclination which evolves over time, so that it is dynamic and biometric. Since the algorithm uses pen-trajectory information...