本間　敬之

掲載種別：研究論文（学術雑誌）

ISSN：13882481

概要：© 2018 In this work, the behavior of an additive designed to aid electrodeposition in through-silicon via (TSV) structures is monitored directly using surface enhanced Raman spectroscopy (SERS). A horizontal via structure with a transparent ceiling (corresponding to the side wall of the TSV) was prepared, which allowed the probe laser to reach the bottom of the structure (corresponding to the opposite side of the TSV wall). Au nanoparticles of size ~5 nm deposited on the bottom of the structure produced a SERS effect and enhanced the Raman signals of chemical species migrating nearby. The diffusion behavior of the additive inside the via structure could be monitored with high sensitivity by detecting these enhanced signals. As a case study, this direct measurement method was successfully used to follow the diffusion of a small amount of Janus Green B, a common additive for Cu electrodeposition. The diffusion coefficient of the additive determined by these measurements turned out to be different to that estimated electrochemically on flat electrodes. One of the advantages of our direct measurement setup is the ability to exclude the undesirable environmental changes that often occur in electrochemical measurements.

ISSN：00189464

概要：© 1965-2012 IEEE. FeCuPt nanodot arrays were fabricated by electrodeposition onto a nanopore patterned substrate fabricated by electron beam lithography (EBL), for the purpose to manufacture and characterize model bit-patterned media. Addition of Cu to FePt was carried out to accelerate the phase transformation of FePt into the L1 0 -ordered phase in order to fabricate nanodot arrays with hard and uniform magnetic properties. Composition of the FeCuPt ternary alloy films was optimized by varying applied potential and CuSO 4 concentration to form single L1 0 phase (40-50 at% Pt and 25 at% Cu). Annealing at 450 °C resulted in the phase transformation from fcc to L1 0 in FeCuPt ternary alloy films, whereas FePt binary alloy films did not show a phase transformation. Perpendicular coercivities of FeCuPt and FePt were 6 and 1 kOe, respectively, annealing at 450 °C, indicating the formation of the L1 0 phase with lower annealing temperature by Cu incorporation. FeCuPt nanodot arrays with 20 nm in diameter and 35 nm in pitch were successfully fabricated with the nanopore patterned substrate fabricated by EBL. In addition, cross-sectional transmission electron microscope analysis of FeCuPt nanodot arrays showed clear stacking of the L1 0 (111) lattice in a perpendicular direction through the growth direction having a single crystal nature, whereas phase transformation was insufficient with FePt nanodot arrays. The collective results have successfully demonstrated the electrochemical fabrication of ultra-fine FePt nanodot arrays with L1 0 structure by promoting L1 0 ordering with Cu additions.

ISSN：10735615

概要：© 2017, The Minerals, Metals & Materials Society and ASM International. The effect of adding Si powder/granules on the electrochemical reduction rate of SiO 2 granules in molten CaCl 2 was investigated. Various starting materials were prepared by mixing different amounts (up to 80 mass pct) of Si powder/granules (four different sizes: <  5, 20 to 100, 100 to 250 µm, 0.5 to 1.0 mm) with SiO 2 granules, with these materials then being electrochemically reduced for 20 minutes in molten CaCl 2 at 0.6 V vs Ca 2+ /Ca and a temperature of 1123 K (850 °C). The effects of the size and amount of Si added on the reaction rates were then studied. When the size of the Si powder added is less than 5 µm, the reaction rate decreases as more Si is added. When Si with a size of 20 to 100 or 100 to 250 µm is used, the reaction rate does not change substantially with the amount added. When 0.5 to 1.0 mm Si is used, the reduction rate is the largest when 40 mass pct Si is added. The reduction rate is influenced by the reaction surface and the diffusion of O 2− ions in the mixture.

ISSN：0021891X

概要：© 2017 Springer Science+Business Media B.V., part of Springer Nature Abstract: In this work, we developed a precise approach to analyze local proton concentration at the solid/liquid interface of electrodes, i.e. “surface pH”, during electrochemical reactions. For this, surface enhanced Raman spectroscopy (SERS) was applied to analyze pH-dependent structural changes of the –COOH group of p-mercaptobenzoic acid (p-MBA) modified onto Au nanoparticles (NPs) on the substrate close to a working electrode. Measurements using this system identified deprotonation of –COOH of p-MBA. Since preliminary experiments and density functional theory calculations suggest that the pKa of p-MBA attached to Au NPs is close to that in bulk solution, the SERS results indicate pH increase due to proton consumption by the cathodic overpotential of the working electrode. As an example, we applied this system to surface pH monitoring in electrodeposition process of Ni in an acidic bath, which indicated the validity of our method for precise detection of pH changes at electrode interfaces in situ. Graphical Abstract: [Figure not available: see fulltext.]

ISSN：13861425

概要：© 2017 Elsevier B.V. The internal structure of self-assembled monolayers (SAMs) such as 3-aminopropyltriethoxysilane (APTES) fabricated on a glass substrate is difficult to characterize and analyze at nanometer level. In this study, we employed surface-enhanced Raman spectroscopy (SERS) to study the internal molecular structure of APTES SAMs. The sample APTES SAMs were deposited with Ag nanoparticles to enhance the Raman signal and to obtain subtler structure information, which were supported by density functional theory calculations. In addition, in order to carry out high-resolution analysis, especially for vertical direction, a fine piezo electric positioner was used to control the depth scanning with a step of 0.1 nm. We measured and distinguished the vertical Raman intensity variations of specific groups in APTES, such as Ag/NH 2 , CH 2 , and Si[sbnd]O, with high resolution. The interfacial bond at the two interfaces of Ag-APTES and APTES-SiO 2 was identified. Moreover, APTES molecule orientation was demonstrated to be inhomogeneous from frequency shift.

ISSN：00134686

概要：© 2017 Elsevier Ltd Effects of Pb and Sn additives on electrodeposition of Zn were investigated for the applications in Zn secondary battery, focused on their roles on morphological evolution. Similarly to well-known effect of Pb addition to smoothly electrodeposit Zn film surface, Sn also exhibited to suppress the formation of mossy structures, which were highly filamentous Zn electrodeposits to cause frequently battery failure. Pb significantly shifted deposition potential of Zn to negative value at concentration less than 1.0 mmol dm −3 , while Sn showed no substantial effect even at 50 mmol dm −3 . The morphological evolution analysis demonstrated that the addition of 1.0 mmol dm −3 Pb significantly altered nucleation behavior of Zn at initial stages of deposition; stacking of layer-like structures (microsteps) were altered to discrete and uniform nuclei of Zn preferentially oriented to (002) direction. In contrast, with Sn additive, morphological features at the initial stage of deposition were similar to that without additive. However, microsteps evolution was gradually suppressed and relatively strong (002) texture of electrodeposited Zn was mitigated by Sn addition. These results suggested that the beneficial roles of Pb and Sn addition on Zn morphological evolution were ascribed to different reasons; Pb diminished the active growth sites of Zn surface by suppressing the deposition reaction of Zn, while Sn suppressed microsteps evolution by different texture evolution of Zn.

ISSN：20403364

概要：© 2017 The Royal Society of Chemistry. The thickness of 3-dimensional (3D) mesoporous silica ultrathin films was controlled at a single-nanometer scale by wet-etching. A drop casting method with an aqueous etchant of ammonium fluoride was effective in etching the surfaces of films in the direction perpendicular to their substrates. The decrease in the film thickness depends on the interface tension of etching solutions. The wettability of thin films also influences the etching. CoPt nanodots were electrodeposited within ultrathin silica films on Ru substrates to form CoPt nanodot patterns.

ISSN：03048853

概要：© 2017 Elsevier B.V. CoPt nanodot arrays were fabricated by combining electrodeposition and electron beam lithography (EBL) for the use of bit-patterned media (BPM). To achieve precise control of deposition uniformity and coercivity of the CoPt nanodot arrays, their crystal structure and magnetic properties were controlled by controlling the diffusion state of metal ions from the initial deposition stage with the application of bath agitation. Following bath agitation, the composition gradient of the CoPt alloy with thickness was mitigated to have a near-ideal alloy composition of Co:Pt =80:20, which induces epitaxial-like growth from Ru substrate, thus resulting in the improvement of the crystal orientation of the hcp (002) structure from its initial deposition stages. Furthermore, the cross-sectional transmission electron microscope (TEM) analysis of the nanodots deposited with bath agitation showed CoPt growth along its c-axis oriented in the perpendicular direction, having uniform lattice fringes on the hcp (002) plane from the Ru underlayer interface, which is a significant factor to induce perpendicular magnetic anisotropy. Magnetic characterization of the CoPt nanodot arrays showed increase in the perpendicular coercivity and squareness of the hysteresis loops from 2.0 kOe and 0.64 (without agitation) to 4.0 kOe and 0.87 with bath agitation. Based on the detailed characterization of nanodot arrays, the precise crystal structure control of the nanodot arrays with ultra-high recording density by electrochemical process was successfully demonstrated.

ISSN：09090495

概要：© 2017 International Union of Crystallography.Total reflection X-ray fluorescence (TXRF) analysis is extensively used by the semiconductor industry for measuring trace metal contamination on silicon surfaces. In addition to determining the quantity of impurities on a surface, TXRF can reveal information about the vertical distribution of contaminants by measuring the fluorescence signal as a function of the angle of incidence. In this study, two samples were intentionally contaminated with copper in non-deoxygenated and deoxygenated ultrapure water (UPW) resulting in impurity profiles that were either atomically dispersed in a thin film or particle-like, respectively. The concentration profile of the samples immersed into deoxygenated UPW was calculated using a theoretical concentration profile representative of particles, yielding a mean particle height of 16.1 nm. However, the resulting theoretical profile suggested that a distribution of particle heights exists on the surface. The fit of the angular distribution data was further refined by minimizing the residual error of a least-squares fit employing a model with a Gaussian distribution of particle heights about the mean height. The presence of a height distribution was also confirmed with atomic force microscopy measurements.

ISSN：13443542

概要：© The Electrochemical Society of Japan, All rights reserved.The thermal stability of graphene has a close relationship with defect generation, thermal oxidation, which in turn have a significant bearing on its properties and applications. This report discusses the effect of confocal laser heating on the structure of single-layer graphene (SLG) on the basal plane and the edge. The thermal stability of SLG basal plane and edge was demonstrated to be different by using in situ anti-Stokes and Stokes Raman spectroscopy. The basal plane was found to be unstable above 500°C, while the edge could not endure even 220°C. The variation in the intensity of D, G, and 2D peaks and the intensity ratios of I(D)/I(G) and I(2D)/I(G) indicated that the thermal instability started with defect generation at the basal plane. The initial point defects at edge were partially eliminated at low temperature and generated again at temperatures above 220°C.

ISSN：1600-5775

ISSN：1344-3542

概要：The thermal stability of graphene has a close relationship with defect generation, thermal oxidation, which in turn have a significant bearing on its properties and applications. This report discusses the effect of confocal laser heating on the structure of single-layer graphene (SLG) on the basal plane and the edge. The thermal stability of SLG basal plane and edge was demonstrated to be different by using in situ anti-Stokes and Stokes Raman spectroscopy. The basal plane was found to be unstable above 500°C, while the edge could not endure even 220°C. The variation in the intensity of D, G, and 2D peaks and the intensity ratios of I(D)/I(G) and I(2D)/I(G) indicated that the thermal instability started with defect generation at the basal plane. The initial point defects at edge were partially eliminated at low temperature and generated again at temperatures above 220°C.

概要：ラマン散乱分光法は非破壊で動的な化学構造の変化を測定することができる．また高速での測定も可能なのでさまざまな外部入力と同時に測定することもできる．本報告では，摺動時の摩擦力などの機械物性とラマンスペクトルを高速で同時測定を行った結果を紹介する．

ISSN：18820778

概要：© 2016 The Japan Society of Applied Physics.We present a novel optical device for the analysis of chemical surface properties utilizing surface-enhanced Raman scattering. The device, a transmission-type plasmonic sensor (TPS), offers the advantages of high sensitivity, nondestructive sample characterization, simple setup, and low-cost fabrication. The TPS is composed of Ag nanoparticles (NPs) deposited on a convex quartz glass substrate. The enhanced Raman spectrum is acquired by focusing a laser beam perpendicular to the sample surface through the substrate. The laser beam generates plasmon polarization in droplet-shaped Ag NPs at the sensor/sample interface. Our results indicate the potential of the device as a versatile surface-analytical tool.

ISSN：1882-0778

概要：We present a novel optical device for the analysis of chemical surface properties utilizing surface-enhanced Raman scattering. The device, a transmission-type plasmonic sensor (TPS), offers the advantages of high sensitivity, nondestructive sample characterization, simple setup, and low-cost fabrication. The TPS is composed of Ag nanoparticles (NPs) deposited on a convex quartz glass substrate. The enhanced Raman spectrum is acquired by focusing a laser beam perpendicular to the sample surface through the substrate. The laser beam generates plasmon polarization in droplet-shaped Ag NPs at the sensor/sample interface. Our results indicate the potential of the device as a versatile surface-analytical tool.

ISSN：00222291

概要：© 2016, The Author(s).We report the fabrication and evaluation of the Cu/Bi bilayer absorber with electrodeposition. We designed the Cu/Bi absorber to satisfy the requirements for scanning transmission electron microscope (STEM). The residual resistivity ratios of films of Cu and Bi with electrodeposition was 5.91 ± 0.49 and 2.06 ± 0.33 , respectively; these values are sufficient for the requirements of STEM. We found that the Cu/Bi bilayer absorber TES microcalorimeter experienced a pulse-shape variation and we considered that these variations were caused by the quality of the contact surface between the absorber and TES. In addition, we examined the structure of the absorber using focus ion beam analysis and STEM. The results suggest that an oxidation between the Cu and seed layer, in which the layer is an electrode for electrodeposition, yielded variations. Moreover, thermal simulation suggests that the thermal conduction between the absorber and TES caused variations. The results of this study will improve the process of Bi electrodeposition.

ISSN：00134686

概要：© 2016 Elsevier Ltd. All rights reserved.The morphological evolution of zinc during electrodeposition from an alkaline zincate solution, i.e., corresponding to charging operation in secondary zinc batteries, was investigated. The initiation and propagation of mossy structures were particularly focused; mossy structures represent one of the undesired, irregular morphologies at low cathodic overpotential. Scanning electron microscopy observations showed that mossy structures formed transiently from layer-like morphology followed by the formation of protrusions with a size of submicrometers. These protrusions still exhibited layer-like features in the initial stage. In addition to this transition behavior, the propagation of mossy structures was monitored in situ by optical microscopy. At -5.0 mA cm-2, mossy structures formed successively and propagated, while there was no clear change in layer-like morphology during deposition outside these characteristic structures. At -20 mA cm-2, the layer-like growth proceeded for longer duration and the population of the mossy structures apparently decreased. However, they continuously increased in size followed by successive formation of mossy structures once initiated. From these results, growth mode of zinc at low cathodic overpotential transiently changed from layer-like growth to mossy structure evolution accompanied with dynamic variations in local current density.

ISSN：19327447

概要：© 2016 American Chemical Society.Theoretical analyses of l-alanine (l-Ala)- and l-homocysteine (l-Hcy)-Cu(II) complexes in basic, neutral, and acidic solutions were carried out using density functional theory to investigate the pH dependence of the formation mechanism of amino acid-Cu(II) complexes. The calculated complex formation energies indicate that the amino acid-Cu(II) complexes were expected to form in basic and neutral solutions but not in acidic solutions. The factors that determine the stability of these complexes are the coordination ability of each amino acid and the significance of intramolecular interactions among ligands within the complexes. As predicted from the molecular structure, in neutral solutions, the coordination ability of amino acid becomes lower than that in basic solutions because of the inert structure of the protonated amino group, -NH3+ however, the coordination ability originating from the -COO- group is estimated to be sufficient for stabilizing the entire complex system. Moreover, two H2O molecules coordinate with the central Cu2+ ion from the equatorial direction and interact with the coordinating amino acids, providing additional stability within the complex. In contrast, in acidic solutions, the complex does not have either sufficient coordination ability of amino acids or effective intramolecular interactions within the complex.

ISSN：00134686

概要：© 2015 Elsevier Ltd. All rights reserved.We have fabricated Co-Pt nanodot arrays by combining electrodeposition with electron beam lithography (EBL) for applications in ultra-high density magnetic recording media, such as bit-patterned media (BPM). In this work, we analyzed the initial nucleation and growth of Co-Pt inside nanopores to achieve nanodot arrays with high deposition uniformity, as well as magnetic properties. At -900 mV (vs. Ag/AgCl), multiple nuclei of 2.0-3.0 nm in size were randomly distributed, even in nanopores with a 10 nm diameter, which could result in a lack of uniformity in the magnetic properties. The number of nuclei was then reduced by applying a less negative potential (>-700 mV vs. Ag/AgCl) to deposit a single nucleus inside each nanopore. As a result, a single grain of 5.0-10 nm in size was successfully deposited inside the nanopore, which could induce uniform magnetic properties in each nanodot. In addition, at less negative potentials, the coercivity of the Co-Pt films increased, which was induced by the epitaxial-like growth of Co-Pt from the Ru substrate. Cross-sectional TEM analysis suggested that Co-Pt deposited with a less negative potential was single crystalline with uniform hcp lattice fringes in the direction perpendicular to the Ru interface, indicating the formation of highly uniform nanodot arrays with high perpendicular magnetic anisotropy.

ISSN：01694332

概要：© 2015 Elsevier B.V. All rights reserved.A structure's temperature can be determined from the Raman spectrum using the frequency and the ratio of the intensities of the anti-Stokes and Stokes signals (the Ias/Is ratio). In this study, we apply this approach and an equation relating the temperature, Raman frequency, and Ias/Is ratio to in-situ estimation of the phase change point of a (3-aminopropyl)triethoxysilane self-assembled monolayer (APTES SAM). Ag nanoparticles were deposited on APTES to enhance the Raman signals. A time-resolved measurement mode was used to monitor the variation in the Raman spectra in situ. Moreover, the structural change in APTES SAM (from ordered to disordered structure) under heating was discussed in detail, and the phase change point (around 118 °C) was calculated.

ISSN：10735615

概要：© 2015, The Minerals, Metals & Materials Society and ASM International.As a fundamental study to develop a new process for producing solar-grade silicon, the effect of granule size on the kinetics of the electrochemical reduction of SiO2 granules in molten CaCl2 was investigated. SiO2 granules with different size ranges were electrolyzed in molten CaCl2 at 1123 K (850 °C). The reduction kinetics was evaluated on the basis of the growth rate of the reduced Si layer and the behavior of the current during electrolysis. The results indicated that finer SiO2 granules are more favorable for a high reduction rate because the contact resistance between the bottom Si plate and the reduced Si particles is small and the diffusion of O2− ions in CaCl2 inside the porous Si shell is easy. Electrolysis using SiO2 granules less than 0.1 mm in size maintained a current density of no less than 0.4 A cm−2 within 20 minutes, indicating that the electrochemical reduction of fine SiO2 granules in molten CaCl2 has the potential of becoming a high-yield production process for solar-grade silicon.

ISSN：00134651

概要：© 2015 The Electrochemical Society.To establish a new Si-electrodeposition process, the optimum conditions for obtaining adherent, compact, and smooth Si films using molten KF-KCl-K2SiF6 were investigated at 923 K. Galvanostatic electrolysis was conducted on a Ag substrate in eutectic KF-KCl (45:55 mol%) with various current densities (10-500 mA cm-2) and K2SiF6 concentrations (0.5-5.0 mol%). Cross-sectional scanning electron microscopy (SEM) of the deposits revealed that compact and smooth Si films form at intermediate K2SiF6 concentrations and current densities. The relationship between the deposition conditions and Si morphology is discussed in terms of the electrodeposition mechanism.

ISSN：19385862

概要：Electrolytic production process for solar-grade Si utilizing liquid Si-Zn alloy cathode in molten CaCl2 has been proposed. Toward the establishment of the process, the behavior of liquid Zn metal was investigated in molten CaCl2 at 1123 K. The evaporation of Zn metal was largely suppressed by an immersion into molten salt, which enables the use of Zn electrode in spite of the high vapor pressure of Zn. The cyclic voltammetry suggested the reduction of SiO2 at 1.45 V vs. Ca2+/Ca on a Zn cathode. After the potentiostatic electrolysis at 0.9 V, Si particles with diameters of 2-30 μm were precipitated in the solidified Zn matrix by the slow cooling process of the produced liquid Si-Zn alloy. The alloying rate between solid Si and liquid Zn was measured as 4.56 μm s-1, and it linearly decreased with the Si content in liquid Zn phase.

ISSN：19385862

概要：Toward an establishment of a new production method of solar cell substrates, electrodeposition of Si was investigated in molten KF-KCl (eutectic composition, 45:55 mol%) after the introduction of SiCl4. Gaseous SiCl4 was directly introduced into the molten salt at 1023 K by a vapor transport method using Ar carrier gas. The dissolution ratio of SiCl4 exceeded 80% even with the use of a simple tube for the bubbling. Galvanostatic electrolysis was conducted at 923 K on a Ag substrate at 155 mA cm-2 for 20 min in molten KF-KCl after the dissolution of 2.30 mol% SiCl4. Although compact Si layer was formed, the smoothness was lower compared to that obtained from the melt after the addition of K2SiF6. The anionic molar fraction is probably one of the factors affecting the morphology of deposit.

概要：© Copyright 2016 by ASME.A chemical depth profile in lubricant films, carbon films, and their interfaces is an informative parameter for hard disk media because molecular features of lubricants bonded to a surface of carbon overcoats (COCs), which usually consist of a nitrogen doped layer, are important to achieve high tribological performance. However, it was difficult to analyze their interfaces with high depth resolution because thickness of lubricant films and COC films are so thin, i.e. 1.5nm and 2nm, respectively. We have developed new method using plasmonic sensors, which has measurement capability for chemical structures with depth resolution of 0.1nm by surface-enhanced Raman spectroscopy (SERS). We examined the lubricant film composed of perfluorinated polyether (PFPE) with phosphazene derivative (A2OH) on a diamond-like carbon (DLC) film. The result shows that the functional group is adsorbed on the DLC surface, where lower shift in the wave number of phenyl group is observed. The depth profile of the intensity ratio of D-peak to G-peak shows the maximum at around the surface of the DLC film. A variety of organic components in the DLC films, fabricated by a chemical vapor deposition (CVD), were observed in it. Besides, the depth profiles shows that organic materials, involving methyl, ethyl, or ethylene groups, Co(OH)x exist in the film.

概要：© Copyright 2016 by ASME.A heat-assisted magnetic recording (HAMR) is expected for a future high density recording of a hard disk drive. However, a carbon overcoat (COC) composed of diamond-like carbon (DLC) or a lubricant film is possibly damaged when a magnetic medium, i.e. CoPt alloy, is heated at around Curie temperature (Tc) of 600K by a near-field HAMR head. We carried out HAMR simulation experiments by using newly developed Raman spectroscopic systems, composed of plasmonic sensors for surface-enhanced Raman scattering (SERS), a pulsed laser heating, and an in-situ temperature measurement with an intensity ratio of anti-Stokes/Stokes lines. It was found that the heated temperature of the COC is higher than that of the magnetic film, i.e., 580°C and 366°C, respectively. Intensity changes of G-band peak in Raman spectra for DLC films were observed during the pulsed laser heating. The Raman intensity was exponentially decreased by oxidation in air, where time constants were calculated as a parameter of a pulse width. Degradation life of the DLC film can be estimated from a critical pulse width, where the time constant is extrapolated to zero. The estimated pulse width for no degradation was 250μs at the heating temperature of 580°C. The result shows no damage can be estimated in DLC films for HAMR because the effective irradiation time is 5ns and the accumulated irradiation time is 0.5ms in HAMR operations.

ISSN：1882-0778

概要：ラマン分光法は、高分解能で化学構造を分析する方法として優れているが、これに高速での動的観察機能を開発して動的機械物性と化学構造の同時観察を試みている。今回は、トライボロジー現象を例に摺動時の摩擦力と化学構造の変化について報告する。

ISSN：0388-5321

概要：

New technique for analyzing buried interface has developed based on surface-enhanced Raman scattering spectroscopy. It consists of plasmonic sensors and spectrometer equipped with high precision mechanisms. Performance of the system involves in-situ measurement of interfaces, i.e. liquid/solid or solid/solid, with high sensitivity and high depth resolution on a variety of samples. Additional functions are in-situ temperature measurement by anti-Stokes/Stokes ratio, simultaneous acquisition with laser heating, time-resolved measurement, and pulsed laser Raman spectroscopy. A depth profile of layered ultra-thin films, i.e. diamond-like carbon (DLC) or highly oriented pyrolytic graphite (HOPG), was analyzed in atomic scale resolution at solid/solid interface. Molecular configuration and bonding feature of liquid organic molecules, i.e. lubricants for magnetic disks or reducing agents for a plating, were analyzed at liquid/solid interface. Oxidation process or decomposition process of ultra-thin DLC films was analyzed for a variety of DLC films. Spectral change with irradiation time by pulsed laser heating exhibited a kinetic change of molecular structures in a chemical reaction with in-situ heating temperature measurement.

ISSN：00134686

概要：© 2015 Elsevier Ltd. All rights reserved.The reaction mechanism of Si electrodeposition in the ionic liquid trimethyl-n-hexylammonium bis(trifluoromethylsulfonyl) imide (TMHATFSI) with SiCl4 was investigated using an electrochemical quartz crystal microbalance (EQCM) and X-ray photoelectron spectroscopy (XPS). The deposited films were further characterized by Raman spectroscopy. The EQCM method measured the frequency change in situ during electrodeposition, whereas XPS provided the Si mass concentration in the electrodeposited films. By combining these results, the mass change due to SiCl4 reduction was estimated. Then, the current efficiency for Si electrodeposition at various potentials was evaluated. The calculated current efficiency was almost 100% when it was assumed that SiCl4 reduction progressed by four-electron electroreduction. The XPS and Raman results showed that the deposited films were composed primarily of amorphous Si with Si-Si bonds. Crystalline Si thin films were obtained after annealing in an Ar gas stream.

ISSN：00134686

概要：© 2015 Elsevier Ltd. All rights reserved. A new approach to produce high purity solar grade silicon (SOG-Si) using wet-chemical and electrochemical processes was proposed. First, diatomaceous earth was used as a source of silica and wet-chemical purification by acid leaching and solvent extraction processes were applied for eliminating heavy metal and light element such as boron, respectively. In particular, the solvent extraction using channel flow reactor demonstrated extremely high efficiency for eliminating boron to 7N (99.99999%) level purity. Secondly, the high-purity silica was reduced to silicon by the direct electrolysis method using molten CaCl2 as an electrolyte and Si plate as cathode. We proposed the continuous electrolysis system by feeding silica granules to the Si cathode set at the bottom of the cell. It was confirmed that the reduction proceeded steadily to form crystalline Si with a sufficient reduction rate. We also attempted electrodeposition of Si films and have developed a process using KF-KCl + K2SiF6 molten salt, from which uniform layer of Si with a thickness larger than 100 μm could be formed.

ISSN：00134651

概要：© 2015 The Electrochemical Society. All rights reserved. A new method for electroplating Si using a water-soluble KF-KCl molten salt electrolyte and high-purity gaseous SiCl4 has been proposed. To gain a fundamental understanding of the process, the electrodeposition of Si from Si(IV) complex ions on a Ag electrode in a molten KF-KCl-K2SiF6 system was investigated by cyclic voltammetry at 923 K. The reduction of Si(IV) ions to metallic Si was observed as a single 4-electron wave, which is explained by an EqEr (quasireversible-reversible electron transfer reactions) mechanism. The diffusion coefficient of the Si(IV) ions in the electrolyte was determined to be 3.2 × 10^-5 cm² s^-1 at 923 K by chronoamperometry.

ISSN：2050-7488

ISSN：0013-4686

ISSN：0013-4651

ISSN：1344-3542

概要：Electrochemical approaches for the fabrication of functional micro–nano structures and devices were comprehensively described primarily on the basis of the results obtained from previous studies conducted by the author's group with the aim of demonstrating the potential for achieving further precise controllability. First, a theoretical study was conducted for investigating the processes, mainly focusing upon electroless deposition to present an approach for analyzing its reaction mechanism from the molecular level. These approaches could be powerful tools for elucidating the overall process and could contribute toward achieving the precise design of processes. Second, some experimental approaches for achieving the precise control of micro–nano fabrication of functional structures, such as maskless and electroless fabrication of metal nano-patterns, lateral enhanced electrodeposition to form ultrathin layers, as well as the nanostructures for various devices by through-mask electrochemical deposition, were introduced to demonstrate high capability of the processes for nanoscale fabrication in various applications.

ISSN：1344-3542

ISSN：00134686

概要：© 2015. The reaction mechanism of Si electrodeposition in the ionic liquid trimethyl-n-hexylammonium bis(trifluoromethylsulfonyl) imide (TMHATFSI) with SiCl4 was investigated using an electrochemical quartz crystal microbalance (EQCM) and X-ray photoelectron spectroscopy (XPS). The deposited films were further characterized by Raman spectroscopy. The EQCM method measured the frequency change in situ during electrodeposition, whereas XPS provided the Si mass concentration in the electrodeposited films. By combining these results, the mass change due to SiCl4 reduction was estimated. Then, the current efficiency for Si electrodeposition at various potentials was evaluated. The calculated current efficiency was almost 100% when it was assumed that SiCl4 reduction progressed by four-electron electroreduction. The XPS and Raman results showed that the deposited films were composed primarily of amorphous Si with Si-Si bonds. Crystalline Si thin films were obtained after annealing in an Ar gas stream.

ISSN：00134651

概要：A novel approach toward the purification of silica and removal of boron impurities via solvent extraction with 2-ethyl-1,3-hexanediol using a microchannel device is presented. The microchannel, fabricated on Si substrates using lithographic techniques, had 100 μm width, 100 μm depth, and 10 mm length. Amorphous silica spiked with a trace amount of boric acid and refined diatomaceous earth used as silica feedstock were purified. Residual boron content was determined by inductively coupled argon plasma atomic emission spectrometry. Following extraction using a microchannel device, the residual boron content was less than 1.0 ppm for the former silica feedstock and than 2.5 ppm for the latter one, and the contact reaction period was 0.03 seconds for both type of silica feedstock. These are lower and significantly shorter due to much shorter diffusion distance and much larger specific interfacial area as compared to those observed when using a conventional separatory funnel, for both types of silica feedstock. Hence, it is suggested that microchannel devices can be utilized as an attractive approach toward the production of high-purity silica as a source for solar-grade silicon. © 2014 The Electrochemical Society. All rights reserved.

ISSN：0013-4651

ISSN：0013-4651

ISSN：1073-5615

ISSN：00134686

ISSN：00134686

概要：To elucidate the influence of surface defects, such as steps, on the oxidation of a reducing agent that is used in the electroless deposition process, we theoretically analyzed the reaction behavior of hypophosphite ion around the defect using density functional theory calculations. The reason why we chose the hypophosphite ion is that it is a typical reducing agent and reacts through a universal reaction mechanism. In this analysis, we focused on the dehydrogenation reaction, which is the rate-determining step in the oxidation pathway. Pd and Cu surfaces were chosen as the metal surfaces, because they exhibit completely different catalytic activity from each other, both experimentally and theoretically. Our calculations showed that the surface defect stabilized the final state of dehydrogenation on both Pd and Cu surfaces, which indicates that the defect accelerates the oxidation of the hypophosphite ion. In the final state of dehydrogenation, dissociated hydrogen adsorbs on the hollow site, which appears on the slope of the defect. More detailed analyses of the final state indicate that the stabilization effect by the surface defect originates from the highly efficient interactions between the dissociated hydrogen and the slope. The molecular orbital structure on this slope is distorted, which leads to high electron density around the slope that enables the highly efficient interactions between the hydrogen and the slope. © 2013 Elsevier Ltd.

ISSN：0913-5685

概要：電解析出法とリソグラフィによりhcp-Co_<80>-Pt_<20>及びL1_0-Fe-Ptの薄膜とナノドットアレイをhcp-Ru(002)/Si基板上に形成し,特性評価を行った.また,初期からの析出制御を目的に,印加電位及びドット径がCo-Ptの析出挙動に及ぼす影響を解析した.電子線描画法を用いたプロセスでは2Tb/in.^2に相当する18nm周期,10nm径のナノドットパターンが均一に形成されていることを確認した.初期析出過程の解析の結果,比較的貴な印加電位(-400mV,-500mV vs Ag/AgCl)では核成長が優先的に生じるため,Co-Ptの粒径が増大する傾向が確認され,印加電位及びドット径によりCo-Ptの粒径制御が可能であることが示唆された.Fe-Pt合金の特性評価の結果,膜厚10nmにおいて9.0kOe,また膜厚25nmにおいて9.8kOeの保磁力が得られ,初期段階からの保磁力の向上が示された.さらに,650℃でのアニール処理により膜厚10nmにおいてL1_0構造への相転移が確認された.UV-ナノインプリント法を用いたプロセスでは,35nm径,100nm周期のFe-Ptナノドットアレイが広範囲に形成されていることを確認した.

ISSN：00214922

概要：A NiP imprinting mold with patterns, whose size is from nanometer to submicrometer (170, 500, and 1000nm diameter), was fabricated by electroless deposition of NiP on a 3-aminopropyltriethoxysilane (APTES) modified master mold. The NiP deposit as a replicate mold was then detached from the master mold. The initial NiP deposition in patterns of the master mold was investigated; moreover, nanoindentation was successfully performed on a single NiP pattern for investigating the hardness. The NiP had a similar grain size in different sizes of patterns of the master mold during the initial deposition, as well as the same hardness of the NiP patterns (approximately 12 GPa) was observed. These results indicated that the initial NiP deposition and hardness of NiP were not size dependent above 170 nm. The surface morphology of the NiP detached from the master mold and NiP pattern of different sizes were investigated as well. © 2013 The Japan Society of Applied Physics.

ISSN：13443542

概要：An electroless NiP imprinting mold was fabricated through replication of a cyclo-olefin polymer (COP) master mold. The NiP was electrolessly deposited on a nanopatterned COP master mold, pretreated by ultraviolet (UV) irradiation prior to modification with 3-aminopropyltriethoxysilane (APTES). The NiP deposit as a "replicate" was then detached from the COP master mold. Additionally, by optimizing the UV irradiation period, APTES could be formed on the COP master mold for electroless deposition without disturbing the nanopattern geometry of the COP master mold. The water contact angle and surface morphology of the COP surface, and the adhesion strength between deposited NiP and the COP surface were investigated. © 2013 The Electrochemical Society of Japan, All rights reserved.

ISSN：13443542

概要：Oxidation of the reductants is a dominant factor in the electroless deposition process. In order to obtain fundamental knowledge about the reaction mechanism of reductant oxidation for more precise control of the solid-liquid interface in this process, we have attempted to characterize the behavior of reductants adsorbed on Cu surface by using plasmon antenna enhanced Raman scattering. The concentric-patterned antenna coated with Cu, which consisted of a dimple array with single hole or a single hole with coaxial dimples, was designed by Finite Difference Time Domain (FDTD) calculation to enhance the electric field by focusing surface plasmons. By using this antenna and comparing the spectra to the results of Density Functional Theory (DFT) calculations, Raman peaks of adsorbed reductants on Cu were identified. Furthermore, we examined the conformation of adsorbed reductants by DFT calculation of the adsorption model of reductants on fcc-Cu(111) surface. As a result, the nature of reductant adsorption on Cu surface has been investigated from a computational point of view and an experimental point of view, and such in-situ characterization will be useful for analysis of a variety of systems at solid-liquid interface. © 2013 The Electrochemical Society of Japan, All rights reserved.

ISSN：00134651

概要：Thiourea is well known and widely used additive for controlling the rate of electroless Ni deposition, and it is known to show complicated behavior in acidic/alkaline electroless deposition baths. To understand this, several experiments and theoretical calculations were performed. In the experiments, the adsorption of thiourea and the reducing agent (i.e., hypophosphite ions) on a Ni surface was characterized with a high-selectivity component at a right angle down to the sub-monolayer level using surface-enhanced Raman spectroscopy. By comparing the results with those obtained from the theoretical calculation, co-adsorption of thiourea and hypophosphite ions on the Ni surface was confirmed. Moreover, the acceleration or suppression effects of thiourea on the oxidation of hypophosphite ions on a Ni surface in acidic/alkaline bath were analyzed from the experimental and computational perspectives. Accordingly, an explanation that unifies both the acceleration and suppression mechanisms of thiourea in terms of its own fundamental characteristics is proposed; this will be one of the most important processes for industrial applications of electroless Ni deposition. © 2013 The Electrochemical Society. All rights reserved.

ISSN：0913-5685

概要：我々は,電気化学的手法である電解析出法とリソグラフィ技術を用いて,ビットパターンメディア(BPM)への応用を目的とした強磁性ナノドットアレイの形成を試みている.本研究では強磁性体としてhcp-Co-Pt(002)とL1_0-Fe-Ptに着目し,下地層としてhcp-Ru(002)層を用いることで,極薄膜での磁気特性向上を試みた.また,電子線描画法により形成したナノドットパターンに対して電解析出法によりCo-Pt及びFe-Ptを充填し,強磁性ナノドットアレイの形成及び初期析出過程の解析を試みた.その結果Ru下地層を用いることで,形成されたCo-Pt薄膜の保磁力向上,結晶性向上が確認された.電子線描画法を用いたプロセスでは2Tb/in.^2に相当する18nm周期,10nm径のCo-Ptナノドットアレイの形成を確認した.初期析出解析を行なった結果,印加電位によりナノドット内におけるCo-Ptの粒径が制御可能であることが示された.Fe-Ptに関しては,アニール処理によりL1_0構造への相転移が確認され,保磁力の向上が示された.

ISSN：00134686

概要：This paper described characterization of hydrazine adsorption on Cu surface with high-selectivity of component at right angle down to single molecular level using a plasmonic antenna enhancing Raman scattering. The antenna deposited by Cu with concentric pattern was designed by Finite Difference Time Domain (FDTD) calculation to enhance the electric field by focusing surface plasmon. By using this antenna, Raman peaks of adsorbed hydrazine on Cu was provided at 385 cm-1. Furthermore, these peaks were only observed at 1-2 nm from the antenna surface which meant that this approach had a potential to define the structure of adsorbed hydrazine just only on the plasmon antenna. The structure of adsorbed hydrazine was gauche-conformation. This data corresponded to the Density Functional Theory (DFT) of adsorption model of hydrazine on fcc-Cu (1 1 1) surface. These results suggest that this method creates a wide range of spin-off effects to the characterization of solid-liquid interface. © 2012 Elsevier Ltd.

ISSN：00134686

概要：The acceleration effect of thiourea on an electroless Ni deposition reaction was analyzed through experimental and theoretical approaches. In the experimental approach, the entire deposition process was physically separated into the anodic and the cathodic reactions by preparing two cells connected by a salt bridge. The cells contained either a bath without metal (Ni) ions or a bath without a reducing agent (hypophosphite ions). The current flowing between the two separated baths increased when thiourea was added only to the anodic reaction bath, which indicated that the acceleration effect of thiourea was mainly on the anodic reaction of the hypophosphite ions. Based on this experimental result, in the theoretical calculation approach, a co-adsorption system consisting of thiourea, hypophosphite, and a Ni metal surface was analyzed using density functional theory. Among all the elementary steps of a hypophosphite reaction, thiourea primarily should promote the adsorption step owing to the following two factors. One was the molecular interaction between thiourea and the hypophosphite ion. The other was the restructuring of the electronic states of the Ni surface owing to the adsorption of thiourea, which enhanced the interaction between hypophosphite and its adsorption site on the Ni surface. © 2012 Elsevier Ltd.

ISSN：00134686

ISSN：00134686

概要：The electrodeposition of silicon from silicon tetrachloride in the hydrophobic room temperature ionic liquid trimethyl-n-hexyl ammonium bis-(trifluoromethylsulfonyl) imide was investigated by cyclic voltammetry and chronoamperometry. In situ electrochemical quartz crystal microbalance (EQCM) impedance spectroscopy was used to estimate the mass of films during deposition. The charge efficiency estimated from EQCM measurements is ∼190-250% for four-electron silicon reduction. However, compositional analysis by XPS shows that the EQCM current efficiency estimates are artificially high due to ionic liquid inclusion in the films. Taking the mass concentration of impurities into account, the best-case estimate of current efficiency is found to be approximately 130% for constant potential deposition, suggesting silicon may not have been completely reduced at the potentials investigated, or a chemical reaction step occurs. We also consider that the EQCM analysis may include too many deviations from assumptions for accurate estimation of mass with the conditions studied. © 2012 Elsevier Ltd.

ISSN：13443542

概要：We demonstrated fabrication of nanogap electrodes with flat and thin Au films by using laterally enhanced growth of Au electrodeposition and applied the electrodes for electrical measurement of poly(3-methylthiophene) (P3MT) nanowires. The Au electrodeposition was performed on microgap electrodes following an organic modification process on an insulator surface of the microgap electrodes. Then, P3MT nanowires were aligned between the nanogap electrodes for transistor property measurement. The result suggested that the fabricated nanogap electrodes were suitable to apply for electrical properties measurement of such organic nanowires because of small difference in height between top of the electrodes and the insulator surface. © The Electrochemical Society of Japan, All rights reserved.

ISSN：1344-3542

ISSN：1932-7447

ISSN：0013-4686

ISSN：0013-4686

ISSN：0013-4686

ISSN：1344-3542

ISSN：1344-3542

ISSN：1344-3542

ISSN：0013-4651

ISSN：0021-4922

ISSN：0013-4686

ISSN：0013-4686

ISSN：0913-5685

概要：4Tb/in2以上の記録密度に対応する極薄潤滑膜/DLC保護膜の化学構造を、プラズモンセンサと表面増強ラマン散乱分光法で測定することに成功した。また膜の深さ方向の化学構造変化も0.1mmの分解能で測定した。

ISSN：00134686

概要：A nanoimprint lithography mold was fabricated through electroless deposition combined with self-assembled monolayer (SAM) modification. To copy nanopatterns as "replicates", NiP was electrolessly deposited on a nanopatterned master mold (made of SiO 2/Si), whose surface was modified with 3-[2-(2-aminoethylamino)ethylamino]propyltrimethoxysilane (TAS). NiP deposits were then manually detached from the mold. SAM improves Pd catalyst coverage for electroless deposition, further improving the morphology of the electroless deposition of NiP on the nanopatterned master mold and controlling the adhesion strength between electroless deposited NiP and the nanopatterned master mold to a level appropriate for smooth detachment. The initial catalyzation process and mechanical properties (such as, the hardness and adhesion strength of the SiO 2 substrate) of electroless deposited NiP were also systematically investigated. © 2012 Elsevier Ltd.

ISSN：13882481

概要：Mechanical stress was applied to a Si single crystal wafer to evaluate the changes in its surface properties arising from the lattice strain induced by mechanical stress. The stress was applied quantitatively to the wafer in order to investigate the correlation between the degree of strain and the electrochemical properties of its surface. Finite element method (FEM) structural analysis was used to estimate the degree of strain on the surface, and the open circuit potential was measured in order to investigate the surface electrochemical properties. The analysis suggested that the surface of the wafer was under tensile strain, and the open circuit potential shifted toward the negative direction with the strain. This indicates that mechanical stress applied to a Si surface can change its electronic properties by changing the surface crystal structure. © 2012 Elsevier B.V.

ISSN：00134686

概要：We investigated the laterally enhanced growth of electrodeposited Au for fabricating nanogap electrodes. To enhance the lateral growth, we carried out electrodeposition over patterned electrodes onto a SiO 2 surface modified with self-assembled monolayers (SAMs) or dendrimers with amine groups. The morphology and thickness of the Au films were controlled by adjusting deposition conditions such as duration, applied potential, and Au ion concentration in the bath. To investigate the mechanism of the laterally enhanced growth, the surface states of SAM- or dendrimer-modified SiO 2 were analyzed by X-ray photoelectron spectroscopy (XPS). The XPS results indicate the existence of organic molecules and Au ions on the SiO 2 surface, which suggests that laterally enhanced growth is induced by the Au ions coordinated on the amine groups of the organic molecules. To further analyze the mechanism of the laterally enhanced growth, we investigated the relationship between the morphology of the laterally enhanced growth of Au and the amount of Au ions on organic molecules. The laterally enhanced growth of Au is expected to be useful for fabricating thin film nanogap electrodes. © 2012 Elsevier Ltd.

ISSN：03698009

ISSN：09151869

ISSN：13443542

概要：The influence of water molecules on the reaction behavior of hypophosphite ion, which acts as a reducing agent for electroless deposition, on metal surfaces was elucidated by calculating the adsorption structure of hydrated hypophosphite ion on a Pd surface using Monte-Carlo simulation and density functional theory calculations. Through geometrical optimization, the most favorable structure of the hydrated hypophosphite ion was obtained, in which six water molecules interact with the oxygen of hypophosphite ion and no water interacts with the hydrogen of hypophosphite ion. Further calculations indicated that the hydrated hypophosphite ion adsorbed on the Pd surface via hvdroaen. © The Electrochemical Society of Japan,.

ISSN：13443542

概要：To elucidate the mechanism of catalytic activity of metal surfaces on the reaction of hypophosphite ions, which act as a reducing agent for electroless deposition, molecular orbital interactions between hypophosphite ions and metal surfaces were analyzed using density functional theory. Pd (111) and Cu (111) were chosen as the surfaces with high and low catalytic activity, respectively. The electronic states of adsorption systems were analyzed using the Mulliken population analysis. The position of the d-band plays a key role in determining the catalytic activity on P-H bond cleavage of hypophosphite. The Pd surface has a d-band near the Fermi level and contains a vacancy; this enables the donation and back-donation effect to occur on the adsorbed hypophosphite and promotes P-H bond cleavage. On the other hand, the Cu surface has a d-band in the deep energy area and contains no vacancy; the donation and back-donation effect is not induced and P-H bond cleavage is not promoted. This difference in the degree of promotion of P-H cleavage is responsible for the difference in the catalytic activity on P-H cleavage and dehydrogenation of hypophosphite ions, which in turn explains the difference in the catalytic activity during the entire hypophosphite oxidation process. © The Electrochemical Society of Japan. All rights reserved.

ISSN：1344-3542

ISSN：1344-3542

ISSN：0013-4686

ISSN：0013-4686

ISSN：1388-2481

ISSN：0912-0289

ISSN：09151869

ISSN：00134686

概要：An electroless deposition process for fabricating CoNiP nanodot arrays (less than 50 nm in height) with high magnetic coercivities was investigated. To fabricate such nanostructures, we improved the crystallinity of the CoNiP deposits in the initial deposition stage by applying an fcc-Cu(1 1 1) underlayer with low lattice mismatch to hcp-Co(0 0 0 2), and an autocatalytic electroless deposition process at the Cu surface was carried out by using dual reducing agents, H2PO2 - and N2H4. CoNiP films demonstrated high perpendicular magnetic coercivities in the initial deposition stage since the highly crystalline hcp(0 0 0 2) CoNiP layers were grown parallel to the Cu underlayers. Nanopatterned substrates were formed by UV-nanoimprint lithography. CoNiP was electroless deposited on the nanopatterned substrates. As a result, CoNiP was deposited selectively from the bottom of the nanopores with few defects in a large area. Perpendicular coercivities higher than 3000 Oe were obtained for nanodots even with heights of 50 nm. Thus, an electroless deposition process that can be used to form nanostructures with high crystallinities in the initial stage without any anomalous deposition was demonstrated. © 2011 Elsevier Ltd. All rights reserved.

概要：Ultra-thin DLC films and lubricant films are requested for high density magnetic recording. It was difficult for Raman spectroscopy to measure their molecular structures because of its low sensitivity. Newly-developed plasmonic sensor successfully acquired Raman spectrum of DLC films or lubricant/DLC interfaces with sub-nanometer thickness. Crystal structure of ultra-thin DLC films were slightly changed compared with that of thick films. Specifically, a graphite-like structure increases with decreasing thickness. It was found that organic and inorganic contaminations exist on a magnetic layer or a magnetic layer/DLC interface. According to the Raman spectrum analysis, a feature of adsorbed lubricant molecules of lubricant on the DLC film was confirmed.

ISSN：00134651

概要：The elementary steps of the reactions of hypophosphite ions with Cu, Ni, and Pd were calculated theoretically using Density Functional Theory (DFT) to demonstrate the reaction mechanism and gain insight at the molecular level. The elementary steps of these reactions are adsorption, dehydrogenation, and oxidation (hydroxyl base attack). In the adsorption step, hypophosphite ions adsorb onto each surface spontaneously with stabilities in the order of Ni (111) > Pd (111) > Cu (111). In the dehydrogenation step, hypophosphite ions dehydrogenate on Ni (111) and Pd (111) with small reaction barriers, whereas they react on Cu (111) with a large reaction barrier. The large reaction barrier on Cu (111) is not compensated for by the adsorption energy on the surface. In the oxidation step, dehydrogenated anions on each metal surface react spontaneously with the hydroxyl base. The reaction barriers on each metal surface in this step are not so significant compared to the adsorption energies on each surface, suggesting that a reaction barrier of hypophosphite ion oxidation should exist in the dehydrogenation step and only be observed for Cu (111). This proposition elucidates the experimental catalytic behaviors of metal surfaces in the electroless deposition process using hypophosphite ions. © 2011 The Electrochemical Society.

ISSN：00134651

概要：In order to elucidate the reactivity difference of hypophosphite ions used as reducing agents for electroless deposition on different metal surfaces, such as Pd and Cu, electronic structures of the activation states of hypophosphite ion oxidation on these surfaces were intensively analyzed by using Density Functional Theory (DFT). In the calculation, we focused on the dehydrogenation reaction which should be a rate-determining step in the elementary reaction steps. From the calculation results, a particular orbital interaction between the hypophosphite ion and the metal surface was observed. On Pd (111), the s-orbital of H in the hypophosphite ion interacts singly with the d- or p-orbital of Pd (111). This interaction induces an anti-bonding interaction between H and P in the hypophosphite ion, which is responsible for P-H cleavage. On the other hand, on Cu (111), the s-orbital of H and the s-orbital of P in a hypophosphite ion interact simultaneously with the p-orbital of Cu (111). This interaction barely induces an anti-bonding interaction between H and P in the hypophosphite ion. Such a difference in orbital interaction structures should be related to P-H cleavage activity and the reactivity difference of hypophosphite ion on each metal surface. © 2011 The Electrochemical Society.

ISSN：0013-4651

ISSN：0013-4651

ISSN：0013-4686

ISSN：00134686

概要：We investigated fabrication processes of magnetic nanodot arrays for the ultra-high density magnetic recording media by using an electrodeposition. A CoZrNb underlayer was sputter-deposited on a glass disk substrate as a soft magnetic underlayer (SUL). Nano-patterns were formed on the substrate by UV-nanoimprint lithography (UV-NIL) and CoPt was electrodeposited into the nano-patterns. For obtaining uniform CoPt nanodot arrays with high perpendicular coercivities, we applied thin Cu intermediate layer on CoZrNb SUL and minimized its thickness. As a result, we obtained CoPt nanodot arrays with 150-nm diameter, 300-nm pitches, and 20-nm heights, which have uniform structures, on the substrates with the construction of Cu (1-2 nm)/CoZrNb (100 nm)/Cr (5 nm)/glass disk. The perpendicular coercivity of the CoPt nanodot arrays was as high as 5.4 kOe. From these results, we showed that the Cu intermediate layer with even 1-2 nm thick considerably improved the deposition condition on the substrates with CoZrNb SUL to successfully fabricate CoPt nanodot arrays with the diameter and pitches of 80 nm and 160 nm with sufficient uniformity. © 2010 Elsevier Ltd. All rights reserved.

ISSN：13443542

ISSN：09151869

概要：The electrochemical behavior of Al-Si alloy films in zincate solution was investigated to elucidate the effects of zincate pretreatment on the Zn morphology and subsequent electroless NiP deposition, which is used for under bump metallization (UBM) in integrated circuit (IC) chip packaging. To investigate the electrochemical behavior of the Al-Si films during the zincate pretreatment, the immersion potential and the surface morphology during Zn and NiP deposition were evaluated using Al-Si electrodes that had been fabricated onto two types of Si substrates with different specific resistances. A heterogeneous point was observed for samples fabricated onto Si substrates with high specific resistance (45-95 Ωm), but no such point was observed on samples fabricated onto Si substrates with low specific resistance (0.00001-0.00002 Ωm). This result suggests that the morphology of the deposits was affected considerably by the specific resistance of the Si substrate.

ISSN：00189464

概要：This paper describes the fabrication process of CoPt nandot arrays on a glass disk substrate with a CoZrNb underlayer as a soft magnetic underlayer (SUL) by using an electrochemical process, and also the analysis on the magnetic properties of these fabricated CoPt nanodot arrays. We formed nano-patterned substrates by UV-nanoimprint lithography (UV-NIL) on the glass disk substrate. CoPt was electrodeposited into the nano-patterned substrates optimizing the electrodeposition condition and bath composition as well as a Cu intermediate layer. The construction of the nanodot arrays were CoPt nanodot arrays (20 nm)/Cu (<5 nm)/CoZrNb (100 nm)/Cr (5 nm)/Glass disk. Magnetic signals were clearly observed on the dc magnetized state and multi domain were observed in each nanodot on the ac magnetized state by magnetic force microscopy (MFM). The perpendicular coercivity of the CoPt nanodot arrays was 430 kA/m. These results showed electrochemical process can be used for the manufacture of magnetic recording media. © 2006 IEEE.

ISSN：13882481

概要：An approach to control the diameter of high-aspect-ratio pores formed into a silicon wafer by an electrochemical etching process is reported. Hole (h +) was involved in the etching reaction and the collection of the h+ was the key factor. Artificial micro-cavities were fabricated on the silicon surface prior to the etching. The depth of the space charge region (SCR), Schottky barrier on the silicon-electrolyte interface, was adjusted regarding the depth of the micro-cavities by applied overpotential and specific resistance of the silicon wafer. The collection of h+ at the tip of the cavity site was widely controlled by the adjusted SCR. Consequently the electrochemically etched domain at the cavity site was actively tuned, and then high-aspect-ratio pore with the controlled diameter was formed. The diameter was tuned by the SCR depth which was controlled by the overpotential and the specific resistance. The diameter tuning mechanism worked under the mask-free condition. © 2010 Elsevier B.V. All rights reserved.

ISSN：0018-9464

ISSN：1388-2481

ISSN：0013-4651

ISSN：0013-4686

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開催地：神奈川

開催地：神奈川

開催地：Kyoto

開催地：島根

開催地：Shimane

開催地：Okinawa

開催地：Okinawa

開催地：Okinawa

開催地：東京

開催地：Cancun

開催地：Cancun

開催地：Cancun

開催地：Cancun

開催地：Cancun

開催地：Cancun

開催地：Cancun

開催地：札幌

開催地：京都

開催地：京都

開催地：京都

開催地：Lausanne

開催地：Lausanne

開催地：Lausanne

開催地：東京

開催地：Santa Clara, CA

開催地：Tokyo

開催地：Orlando, FL

開催地：大阪

開催地：大阪

開催地：大阪

開催地：大阪

開催地：大阪

開催地：東京

開催地：千葉

開催地：千葉

開催地：千葉

開催地：千葉

開催地：Tokyo

開催地：東京

開催地：東京

開催地：San Francisco, CA

開催地：San Francisco, CA

開催地：San Francisco, CA

開催地：San Francisco, CA

開催地：San Francisco, CA

開催地：東京

開催地：東京

開催地：東京

開催地：福岡

開催地：福岡

開催地：東京

開催地：Kobe

開催地：Toronto, Ontario

開催地：Pretoria

開催地：神奈川

開催地：宮城

開催地：宮城

開催地：宮城

開催地：宮城

開催地：宮城

開催地：宮城

開催地：埼玉

開催地：Kumamoto

開催地：東京

開催地：Honolulu, Hawaii

開催地：Honolulu, Hawaii

開催地：Honolulu, Hawaii

開催地：Honolulu, Hawaii

開催地：Honolulu, Hawaii

開催地：Honolulu, Hawaii

開催地：Honolulu, Hawaii

開催地：北海道

開催地：北海道

開催地：北海道

開催地：Linz

開催地：Linz

開催地：東京

開催地：Lübeck

開催地：Seattle, WA

開催地：Seattle, WA

開催地：浜松

開催地：浜松

開催地：浜松

開催地：浜松

開催地：浜松

開催地：浜松

開催地：東京

開催地：東京

開催地：東京

開催地：東京

開催地：川崎

開催地：川崎

開催地：東京

開催地：東京

開催地：Boston, MA

開催地：愛知

開催地：Kyoto

開催地：Kyoto

開催地：Kyoto

開催地：Nigata

開催地：Nigata

開催地：Nigata

開催地：Nigata

開催地：Nigata

開催地：新潟

開催地：Tokyo

開催地：Yokohama

開催地：Montreal, QC

概要：電気化学会編集により，種々の電気化学的測定手法について，これから実際に測定を行おうとしている卒業論文生あるいは大学院生の手引きとなることを目的とした書であり，電気化学の初歩から実際の適用例を詳細に解説している．全164ページ．このうち4.5章無電解めっき法を担当し，熱力学的見地からの反応機構の基礎やその解析法，種々のめっき浴系の特徴，さらに無電解反応系を用いた薄膜形成と評価の実際などについて，自分のこれまでの教育指導経験を基に，つまずきやすいところの丁寧な解説に留意しながら詳細に解説している(p.135〜142)．

概要：表面技術協会編集による, 湿式法から乾式法まで様々な薄膜形成手法および表面処理手法の理論と応用を網羅したものであり，主に表面処理工学を初めて学ぶ学部高学年生・大学院生および実務者を対象とした教材である．全280ページ．このなかで3.2章「無電解めっき」を執筆した．無電解めっき法の基礎理論および形成される薄膜のナノ構造と機能特性発現機構の相関，さらに種々の機能デバイスへの応用について述べた．第3章3.1項ウェットプロセスの種類と特徴(p.25〜27)および3.2項無電解めっき(p.47〜51)を執筆した．

概要：電気化学会の編により「電気化学および工業物理化学（電気化学会誌）」に連載で掲載された，電気化学分野の初学者を対象とした「ケーススタディ　電気化学における測定と評価」の第１章として，「機能性薄膜材料の評価(1)磁性薄膜材料」を執筆した（電気化学および工業物理化学，63巻，p.281〜285）． 磁性薄膜材料の作製法およびその微細構造と磁気特性の相関の解析，特性向上のための材料設計指針などについて，自らのデータを中心に実例を取り上げながら解説した．

概要：表面技術協会の編により同協会誌に連載で掲載された「シリーズ／薄膜の物理的性質評価」の第３章として，磁性薄膜材料評価法について執筆した（表面技術，40巻，p.1234〜1238）．物理系の専攻でない学生の入門用教材として適切な内容となるよう，磁性の基礎からその測定法の概略，また各種磁性薄膜の特性評価法について平易に解説した．

概要：第５２回応用物理学関係連合講演会における「これからの物理教育・科学教育シンポジウム」において，日本化学会・化学教育協議会・化学グランプリ・オリンピック委員会委員長として，全国高校化学グランプリ及び国際化学オリンピックに対するこれまでの取り組みと現状，および今後の展望を説明した（依頼講演）．