神田 一浩

We evaluated the growth characteristics of amorphous carbon (source gas: C14H10) fabricated by focused-ion-beam (FIB) and electron-beam (EB) chemical-vapor-deposition (CVD) in the same apparatus environment. All experiments were carried out in a Ga FIB and SEM composite system. It is confirmed that there are some differences in the surface appearance of pillars fabricated by FIB-CVD and EB-CVD. The rate at which an FIB-CVD pillar grows is about 100 times faster than that of an EB-CVD pillar. We found FIB-CVD wiring has electrical conductor properties with a resistivity of 380 Q cm, and EB-CVD wiring has electric-insulator properties. Furthermore, we demonstrated by fabricating spring-shape features that FIB-CVD is superior to EB-CVD for making 3D structures. (c) 2006 Elsevier B.V. All rights reserved.

Our group wants to achieve subcellular manipulations and analysis in nano-space. Highly functional bio nano-tools are required to achieve this. Thus, it is necessary to make these tools three-dimensional nano-structure devices with focused-ion-bearn chemical-vapor-deposition (FIB-CVD) to optimize their performance. FIB-CVD is a key technology for fabricating three-dimensional structures. Two kinds of bio nano-tools were developed for subcellular manipulations and analysis. The first was a cell wall cutting tool (CWCT) to selectively cut cell walls in local areas. That is, cell walls could be removed without damaging subcellular organelles with CWCT. We succeeded in doing this. We also fabricated a filtering tool with a nano-net structure on a glass capillary to capture subcellular organelles. We conducted a successful experiment on capturing chloroplasts in a cell with the filtering tool. (c) 2006 Elsevier B.V. All rights reserved.

The chemical composition and components of a polytetrafluoroethylene (PTFE) surface was investigated as a function of the temperature under the irradiation of synchrotron radiation (SR) by the X-ray photoelectron spectroscopy (XPS). When the temperature of PTFE tinder the SR irradiation was less than 100 degrees C, the C-rich surface appeared. With increasing the temperature more than 150 degrees C, the relative intensity of the F 1s peak to the C1s peak increased markedly. At the temperatures of 150-180 degrees C, the C-C component became small and the CF(2) component was dominant. With further increasing the temperature more than 200 degrees C, CF(3), CF and C-CF components grew in addition to CF(2) component. Based on these XPS results, the temperature effect on the chemical composition and components is discussed. (c) 2005 Elsevier Ltd. All rights reserved.

Local structures of diamond-like carbon (DLC) films formed by various methods were studied by near-edge X-ray absorption fine-structure (NEXAFS) spectroscopy. The DLC films are characterized by the sp(2)/sp(3) ratio, which influences the mechanical and electronic properties. NEXAFS spectroscopy is sensitive to the sp(2)/sp(3) ratio, because the isolated peak corresponding to the 1s ->pi* resonance transition can be observed. Carbon K-edge NEXAFS spectra for DLC thin films, which were synthesized by various methods, were measured using the total electron yield mode in the range of 275 eV-320 eV. A peak due to the coupling of carbon with oxygen was observed in the spectra of some DLC films, whereas it was not observed in the spectra of hydrogenated carbon films formed by RF sputtering. The obtained relative sp(2) contents of the DLC films were distributed in the range of approximate to 20%. The minimum sp(2)/sp(3) ratio was obtained from DLC films formed by vacuum arc deposition from graphite, and large sp(2)/sp(3) ratios were obtained from DLC films formed by plasma chemical vapor deposition from hydrocarbons. The local structure of a DLC film was concluded to depend on the synthesis method, and in particular, the carbon source material.

High-performance nanotools are very important for nanoscale operation and analysis in the various research studies. To improve the performance of these tools, it is necessary to make three-dimensional (3-D) nano structure devices. We fabricated a 3-D electrostatic nanomanipulator with SiO2/DLC heterostructure by focused-ion-beam chemical vapor deposition (FIB-CVD). In this article, we report on the fabrication and movement check of the 3-D electrostatic nanomanipulator.

Synchrotron radiation (SR) process for the production of hydrophilic surface on PTFE sheet was examined by the SR irradiation using the gas cell filled with O-2 gas. High hydrophilic surface was obtained by the SR irradiation under the O-2 gas atmosphere. O atoms existing hydrophilic surface were considered to couple dominantly to PTFE surface during the SR exposure. (c) 2005 Elsevier B.V. All rights reserved.

Photodissociation of cyanogen halides, ClCN, BrCN and ICN, was investigated using synchrotron radiation. The absolute cross-sections for the photoabsorption and the production of CN((BE+)-E-2-Sigma E-2(+)) emission were determined in the wavelength range of 50-180 nm (200,000-55,000 cm(-1)). The observed photoabsorption spectra displayed congested structures, indicating the presence of a number of Rydberg states in the energy region under the second ionization potential. No structures were observed beyond the second ionization potential. The quantum yield for the CN(B-2 Sigma(+)) production first increased with excitation energy and then suddenly decreased at the excitation wavelength corresponding to the opening of the ionization channel. (c) 2005 Elsevier B.V. All rights reserved.

We have investigated the Au-Si(1 0 0) interface as a function of the An coverage by means of the valence band and Au 4f core-level photoemission spectroscopy. At the initial stage of the An deposition, deposited An atoms are close to the atomic An. With increasing the An coverage, it is considered that the An silicide is formed by the influence of the substrate Si atoms. From the relative intensity ratio of the An 4f core-level spectrum to the Si 2p core-level spectrum, the appearance of the 3D islands was suggested at more than 12 ML. This means that the An deposited surface is not homogeneous. In addition, it was found that there are two chemically different Au silicide components from the curve fitting analysis of the An 4f core-level spectrum at the higher Au coverage. (c) 2005 Elsevier B.V. All rights reserved.

Focused-ion-beam chemical vapor deposition (FIB-CVD) is an excellent technology for forming a free-space-nanowiring. At 295 K the electrical resistivity of a free-space-nanowiring made using phenanthrene as the source gas was $1\times 10^{2}$ $\Omega$ cm. Adding tungsten hexacarbonyl to the phenanthrene reduced the electrical resistivity to $2\times 10^{-2}$ $\Omega$ cm. The nanomechanical switch composed of a coil and a nanowiring has been fabricated by using free-space-nanowiring fabrication technology, and its operation has been confirmed by applying a voltage.

Photoexcitation process leading to a variation in the wettability of a poly(tetrafluoroethylene) (PTFE) surface induced by synchrotron radiation (SR) exposure in the soft X-ray region was investigated. It was found that two types of photoexcitation, that is, the formations of a hydrophobic surface and a hydrophilic surface, proceed on the PTFE surface with the exposure to SR. The formation rate of the hydrophobic surface strongly depended on substrate temperature.

High performance nano-tools are very important for nano-scale operations and analysis in various researches. To achieve best performance, tools should be made as three-dimensional (3-D) nano-structured devices. Therefore, we have fabricated 3-D nano-tools by using focused-ion-beam chemical-vapor-deposition (FIB-CVD). Most recently, we used FIB-CVD to fabricate a novel 3-D nano-tool, a nano-net. Using this nano-net, we successfully captured polystyrene microspheres (diameter: 2.0 mu m). (c) 2005 Elsevier B.V. All rights reserved.

The Morpho-butterfly wing reflects interfered brilliant blue, which originates from nanostructures on its scales, for any incidence angle of white light. We have, for the first time, fabricated a Morpho-butterfly-scale quasi-structure using focused-ion-beam chemical-vapor-deposition (FIB-CVD) and observed brilliant blue reflection from this quasi-structure with an optical microscope. We measured the reflection from real Morpho-butterfly scales and from the quasi-structure with a photonic multi-channel spectral analyzer system. The reflection spectra of the quasi-structure were very similar to those of Morpho-butterfly scales.

Nano-tools are very important for the subcellular operation and analysis in the bio-experiments. For giving the high-performance to nano-tool, we think that it is necessary to make tools the three-dimensional (3-D) nano-structure devices. Therefore, we have performed the 3-D nano tools fabrication by using Focused-Ion-Beam Chernical-Vapor-Deposition (FIB-CVD). This time, a nano-net as a novel 3-D nano-tool was fabricated by using FIB-CVD. And we succeeded in scooping the polystyrene micro-sphere witha diameter of 2.0 mu m by using a nano-net.

Nanoimprint lithography (NIL) Si molds with protrusion- and hollow-defects were repaired by Ga+ focused-ion-beam (FIB) direct etching and chemical-vapor-deposition (CVD). The usability of the repaired mold was confirmed by carrying out NIL on poly(methylmethacrylate) (PMMA). After the NIL process, Ga grains appeared on the etching-repaired mold, which was confirmed by scanning electron microscopy-energy dispersive spectrometry (SEM-EDS). The thresholds of ion dose and annealing temperature for Ga grain appearance are studied.

The three-dimensional (3D) nanostructure fabrication technology using focused ion beam chemical vapor deposition (FIB-CVD) is very effective for highly efficient 3D nanomechanical device fabrication. We can fabricate 3D nanostructure easily and freely with this fabrication technology using FIB-CVD. Here, we demonstrate the fabrication of various 3-D nano-electrostatic actuators and manipulators on a glass capillary by 30 keV Ga+ focused-ion-beam-assisted deposition with phenanthrene vapor as a precursor, and the operation of these actuators and manipulators by applying voltage onto a Au-coated glass capillary under an optical microscope is shown. Furthermore, the structural characteristics and functionalities of them are described in this paper.

We have investigated the Au-Si(1 0 0) interface as a function of the An coverage by means of the Si 2p core-level photoemission spectroscopy. At the 1 ML deposition, the spectral feature changed remarkably. This indicates that the deposited An atoms interact with the surface Si atoms in this deposition range. With increasing the Au coverage at similar to3 ML the spectral feature become three-peak structures at 100.0, 99.4, and 99.0 eV. The appearance of the three-peak structures indicates the Au-Si alloy or Au silicide formation. With further increasing the An coverage, two peaks at 100.3 and 99.7 eV become dominant. From the curve fitting analysis, the photoemission spectrum at the higher An coverage was decomposed by three components. Two components at higher binding energy side were assigned to the surface Si atoms while a component at lower binding energy side was assigned to Si atoms in the amorphous silicide layer. (C) 2004 Elsevier B.V. All rights reserved.

The surface modification of a polyimide (PI) sheet using synchrotron radiation (SR) was carried out. The PI sheet was irradiated to white radiation ranging between 50-1000 eV in a vacuum chamber. The contact angle of the PI surface with a water droplet was found to decrease from 75 to 58 by the SR irradiation. The variation of chemical components of the PI surface was studied using X-ray photoelectron spectroscopy (XPS). The ratio of peak intensity from the O1s orbital to that from the C1s orbital increased remarkably by SR irradiation. The increase of wettability on the PI surface was ascribable to the production of an O-rich surface by SR irradiation in the soft X-ray region.

To study the influence of the flux ratio of C60 molecule to Ar cluster ion on DLC film characteristics, DLC films deposited under various flux ratios were characterized with Raman spectrometry and Near Edge X-ray Absorption Fine Structure (NEXAFS). From results of these measurements, hard DLC films were deposited when the flux ratio of C60 to Ar cluster ion was between 0.7 and 4. Furthermore the DLC film with constant sp2 content was obtained in the range of the ratio from 0.7 to 4, which contents are lower values than that of conventional films such as RF plasma. DLC films deposited under the ratio from 1 to 4 had hardness from 40 to 45GPa. It was shown that DLC films with stable properties of low sp2 content and high hardness were formed even when the fluxes were varied from 1 to 4 during deposition. It was indicated that this process was useful in the view of industrial application.

Near-edge X-ray absorption fine structure (NEXAFS) spectra were measured for the optimization of synthesis conditions on the production of diamond-like carbon (DLC) thin films by the Ar gas cluster ion beam (GCIB) assisted deposition of fullerene. The sp2 contents of DLC films were estimated from the analysis of the peak corresponding to the transition of the excitation electron from a carbon 1s orbital to a π∗ orbital in the NEXAFS spectrum of the carbon K-edge over the excitation energy range 275-320 eV. Substrate temperature and Ar cluster ion acceleration voltage in the synthesis conditions of DLC films were optimized to make the sp2 content minimum.

In order to study the influences of Ar monomer ion (Ar+) on carbon film properties induced by ion beams assisted deposition, Ar cluster ion, Ar+, and their mixed ions (Ar cluster ion and Ar+) irradiated surface during evaporation and deposition of C60. From Near Edge X-ray Absorption Fine Structure (NEXAFS) and Raman spectroscopy measurements, lower sp2 content in carbon films was obtained via Ar cluster ion beam bombardment in comparison with bombardment by Ar+ and mixed ion beams. Furthermore higher hardness and smoothness of surface were demonstrated via Ar cluster ion bombardments. Thus, it was important to irradiate using higher fraction Ar cluster ions in the beam, in order to obtain hard DLC films with flat surface.

Three-dimensional diamond-like carbon (DLC) mold fabricated by focused-ion-beam chemical vapor deposition (FIB-CVD) using a precursor of phenanthrene has been applied to a nanoimprint process. Various 3D nanostructure DLC molds have been delineated by FIB-CVD using a computer-controlled pattern generator which is a commercially available pattern generator for electron beam lithography. Then, the molds were imprinted into hydrogen silsequioxane (HSQ) as a material replicated at room temperature. It was confirmed that the 3D mold, after nanoimprint lithography (NIL), kept its original shape, and 3D mold structures were successfully imprinted into HSQ. These results reveal that the 3D mold fabricated by FIB-CVD can be applied to NIL.

Three-dimensional nanostructures on a glass capillary have a number of useful applications such as manipulators and sensors in the various microstructures. This time, we have demonstrated the fabrication of a nozzle nanostructure on a glass capillary for a bio injector by 30 keV Ga+ focused-ion-beam assisted deposition with a precursor of phenanthrene vapor and etching. It has been demonstrated that nozzle nanostructures with various shapes and sizes have been successfully fabricated. An inner tip diameter of 30 nm on a glass capillary and a tip shape with an inclined angle have been realized.

Diamond-like carbon (DLC) film deposited using C-60 vapor with simultaneous irradiation of an Ar cluster ion beam was characterized by a near edge X-ray absorption fine structure (NAXAFS), in order to optimize the hard DLC film deposition conditions. Contents of sp(2) orbitals in the films, which were estimated from NAXAFS spectra, are 30% lower than that of a conventional DLC film deposited by a RF plasma method. Those contents were obtained under the flux ratio of the C60 molecules to the Ar cluster ions to range from 1 to 20, at 5 keV of Ar cluster ion acceleration energy. Average hardness of the films was 50GPa under these flux ratios. This hardness was three times higher than that of a conventional DLC film. Furthermore, the lowest sp2 content and above-mentioned high hardness were obtained at room temperature of the substrate when the depositions were performed in the range of the substrate temperature from room temperature to 250 degreesC.

The effect of synchrotron radiation (SR) irradiation of a polytetrafluoroethylene (PTFE) surface was investigated using X-ray photoelectron spectroscopy (XPS). After the SR irradiation, the relative intensity of the F 1s peak to the C 1s peak decreased markedly. The chemical composition ratio of the F atoms to C atoms was estimated to be 0.29. From the curve fitting analysis of C 1s and F 1s XPS spectra, the chemical components and their intensity ratio were determined. The reason for the chemical composition change by the SR irradiation was discussed.

In this paper, we report fabrication and electrical evaluation of various air-wirings formed by FIB-CVD. The FIB system utilizing a beam of 30 keV Ga/sup +/ ion was applied to make air-wiring. We fabricated two kinds of air-wirings. One was fabricated using two phenanthrene (C4H10) source gases. The other was fabricated using a mixture gas of tungsten carbonyl (W(CO)6) and C4H10 source gases. Then the electrical resistivities were compared.

We present a nanoimprint lithography (NIL) Si mold repair by Ga focussed ion beam (FIB). From the results, we conclude that a Si mold with projection and hollow defects can be repaired by Ga/sup +/ FIB. Ga appearance on a Si mold surface was clearly observed in NIL at over around 150 /spl deg/C.

We have studied the surface modification of synthetic organic polymers using the exposure of SR. Polymers such as polytetrafluoroethylene (PTFE), which is known as a hydrophobic material, and polyimide, which is known to have high heat resistance, are studied.

We have developed a nano-manipulator that can perform inclusion of nano parts and cell operation and an actuator that can be used by the micro- and nano-system by FIB-CVD.

The coordination of the carbon atoms in the diamond-like carbon (DLC) films formed by Ar gas cluster ion beam (GCIB) assisted deposition of fullerene was investigated using synchrotron radiation. Near-edge x-ray absorption fine structure (NEXAFS) spectra of the carbon K-edge of the DLC films formed by various methods were measured over the excitation energy range 275-320 eV, using synchrotron radiation. On the basis of the analysis of the peak corresponding the transition of the excitation electron from carbon Is orbital to pi* orbital, relative sp(2) contents of various DLC films were determined. The DLC films formed by Ar GCIB assisted fullerene deposition were found to consist of a high sp(3) hybridized carbon.

Diamond Like Carbon (DLC) films were formed by Ar cluster ion beam assisted vapor deposition of C60. To study the effects of contaminating Ar monomer ions (Ar) in the cluster beam on the sp2 content, film hardness, and surface morphology of the films, beams of Ar cluster ions, Ar+, and a mixture of cluster ions and Ar+ were used for the bombardment, during evaporation of C60. From the Near Edge X-ray Absorption Fine Structure (NEXAFS) and Raman spectroscopy measurements, lower sp2 contents in carbon films were obtained for the cases when Ar cluster ion beams were used. The usage of single Ar+ and mixed ion beams showed higher sp2 contents. Furthermore, higher hardness and smoother surfaces were obtained with Ar cluster ion irradiations. Therefore, the increase of the fraction of Ar cluster ions in the beams was important to obtain hard DLC films with flat surfaces.

The degrees of freedom in designing their shapes will be a great advantage in Focused-Ion-Beam Chemical-Vapor-Deposition (FIB-CVD), as we previously demonstrated with several three-dimensional nanostructures, i. e., wine glasses, coils, and pillars. Moreover, a very large Young's modulus were confirmed by observation of DLC pillar mechanical vibration. These characteristics are very useful for various biological devices. We will report fabrication of Nano Bio-Injector by using FIB-CVD.

Hard diamond-like carbon (DLC) films have outstanding characteristics with extremely thin film thickness, and will be required for various nano-scale devices. The requirements of this coating are high hardness, smooth surface, and low friction coefficient with thin film thickness below a few nm. The present films made with plasma enhanced CVD process will not be sufficient for hardness to achieve higher recording density in the future. To make films satisfying the above demands, a new method employing Ar cluster ion beam assisted deposition was proposed.

We found that Spin-On-Glass (SOG) material acts as positive-type electron beam resist, and 200 nm line pattern was obtained using 100 nm beam diameter electron beam exposure and following buffered HF (BHF) development. Our previous report, (Jpn. J. Appl. Phys., vol.41, p.4304-4306, (2002)), direct etching of SOG by synchrotron radiation (SR) was confirmed, however, etching rate of polymethylmethacrylate (PMMA) was much higher than that of SOG. Therefore, SOG is the candidate material for high aspect ratio and fine pattern mask to organic materials such as PMMA by SR exposure. In this report etching of PMMA by SR using SOG mask was examined.

Fluorocarbon polymers are fluorishingly used as the material for industry from some characteristic advantages - chemical stability, thermal stability, excellent electric property and so on. One of other characteristics of fluorocarbon polymers was hydrophobicity of these surfaces, and fluorocarbon polymers were applicable to various industrial yields by taking advantage of this characteristic. However, in the several yields, such as painting and adhesion, this hydrophobicity has restricted the application of fluorocarbon polymers. In the present study, wettability on the surface of polytetrafluoroethylene (PTFE) chip was modified by exposure to synchrotron radiation (SR). This is the first report on SIR exposure effects about wettability of PTFE.

Nanoimprint lithography (NIL) is a very useful technique by which the fabrication of various nanostructure devices. A conventional mold is delineated by EB lithography and dry etching which has usually two-dimensional (2-D) patterns. 3-D structures are required in various devices such as optical devices (micro-lenses, photonic crystals, etc.). FIB-CVD is very useful to fabricate 3-D structures, as we previously demonstrated with several 3-D nanostructures. Moreover, a very large Young's modulus over 600 GPa were confirmed by observation of diamond-like carbon (DLC) pillar mechanical vibration. These characteristics are advantageous to make 3-D mold. In this paper, we will report 3-D NIL using DLC mold by FIB-CVD. We used a commercial available FIB system (SMI9200: Seiko Instruments Inc.) a 30-keV beam of Ga ions was focused on the substrate, which was in a precursor ambient. We used phenanthrene (C14H10) as the source gas for the amorphous DLC growth.

DLC films formed by gas cluster ion beam (GCIB) assisted deposition were investigated by NEXAFS using synchrotron radiation.

Summary form only given. As device feature size is reduced, minimizing power dissipation, crosstalk noise and propagation delay due to resistance-capacitance (RC) coupling becomes significant because of increased wiring capacitance, in particular, interline capacitance between metal lines on the same metal level. In order to mitigate the problem of RC delay and crosstalk, interlayer dielectrics (ILDs) with low-dielectric-constant (low-k) are required. Many kinds of low-k dielectrics can be obtained either organic or inorganic materials, dense or porous, and can be deposited by either chemical vapor deposition (CVD) or spin-on techniques. In addition, good electrical, chemical and thermal properties are required for these materials. To improve these properties, plasma treatment and dry etching of low-k dielectrics, plasma oxidation of porous ILDs and electron-beam curing of low-k dielectrics to prevent water absorption have been reported. However, synchrotron radiation (SR) etching has not been reported. Therefore, we carried out the SR exposure of SOG and successfully obtained photoexcited etching of SOG for the first time.

Three-dimensional nanostructure fabrication has been demonstrated by 30 keV Ga+ focused ion beam assisted deposition using a aromatic hydrocarbon precursor. The characterization of deposited film on a silicon substrate was pet-formed by a transmission microscope and Raman spectra. This result indicates that the deposition film is a diamondlike amorphous carbon. Production of three-dimensional nanostructure is discussed. Microcoil, drill, and bellows with 0.1 mum dimension were fabricated as parts of the microsystem. Furthermore, microstructure plastic arts is advocated as a new field using microbeam technology, presenting one example of a microwine glass with 2.75 mum external diameter and 12 mum height. (C) 2000 American Vacuum Society. [S0734-211X(00)06806-2].