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Volume 50, Issue 3
47th Vacuum Symposium Proceedings (Osaka 2006)
Displaying 1-23 of 23 articles from this issue
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Letters
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Qiang ZHANG, Shizuyasu OCHIAI, Goro SAWA, Asao OHASHI, Kenzo KOJIMA, Y ...2007 Volume 50 Issue 3 Pages 155-157
Published: 2007
Released on J-STAGE: January 01, 2008
JOURNAL FREE ACCESSWe have investigated copper phthalocyanine (CuPc) thin-film transistors (TFTs) at different substrate temperatures. X-Ray diffraction (XRD) and UV/Vis spectrometer were used to study the orientations and optical transmission spectrum of the copper phthalocyanine film which was adopted as the semiconductor layer of organic thin-film transistor. A circuit diagram was constructed to study the output characteristics of CuPc TFT with a polycarbonate (PC) gate dielectric layer. The mobility of CuPc TFT at a substrate temperature of 90°C was 1.25×10-4 cm2/Vs. The On/Off ratio was also improved when the substrate temperature increases. Threshold voltages were -17 V at a substrate temperature of 70°C and -30 V at 90°C.
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Yoshinori HIGASHIMURA, Masataka NAKAMURA, Tomoya OKUNO, Hideaki AGURA, ...2007 Volume 50 Issue 3 Pages 158-160
Published: 2007
Released on J-STAGE: January 01, 2008
JOURNAL FREE ACCESSApproximately 300 nm-thick transparent conducting zinc oxide (TCO) films with a stacking structure of ITO (150 nm) and AZO (150 nm) have been deposited on glass substrates at various temperature. When fabricated with oxygen partial pressure of 0.5 Pa for ITO layer and 0 Pa for AZO layer at substrate temperature of 220°C, the lowest resistivity of 2.04×10-4 Ω•cm and the sheet resistance of 6.83 Ω/□ were obtained for the TCO films. These data were almost the same to that of 300 nm-thick ITO films, which was useful to the reduction of rare indium element.
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Fabrication of Transparent Conducting ZnO Film on Organic Substrates with Buffer Layer by PLD MethodKenji UEHARA, Atsuhiro NAKAMURA, Hideaki AGURA, Akio SUZUKI, Takanori ...2007 Volume 50 Issue 3 Pages 161-163
Published: 2007
Released on J-STAGE: January 01, 2008
JOURNAL FREE ACCESSApproximately 390 nm-thick Al-doped transparent conducting zinc oxide films (AZO) have been deposited on substrates with Al2O3 buffer layer (20~505 nm-thick) by pulsed laser deposition (PLD) using ArF excimer laser (λ=193 nm). When fabricated with oxygen partial of pressure 1.3 Pa, the lowest resistivity obtained was 6.99×10-4 Ω•cm. Also, approximately 240 nm-thick Ga-doped transparent conducting zinc oxide films (GZO) have been deposited on substrates with Ga2O3 buffer layer. The lowest resistivity of 2.86×10-4 Ω•cm was obtained at oxygen partial of pressure 0.9 Pa.
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Shigeharu TAMURA, Masato YASUMOTO, Nagao KAMIJO, Yoshio SUZUKI, Akihis ...2007 Volume 50 Issue 3 Pages 164-166
Published: 2007
Released on J-STAGE: January 01, 2008
JOURNAL FREE ACCESSA multilayer (sputtered-sliced) Fresnel zone plate (FZP) is one of promising focusing optics for high-energy X-rays. In order to attain high diffraction efficiency, two types of multilevel-type multilayer FZPs have been fabricated, and these focusing characteristics have been measured at SPring-8. The FZPs composed of concentric multilayers of alternating high-Z(Cu), low-Z(Al), and several types of composite materials layers by Cu and Al. As a result, (1) no significant difference was observed both the measured beam size and the diffraction efficiency of a FZP during 9 months to the FZP with 4-step structure, (2) the diffraction efficiency of the 1st order focus and the focused beam size measured by the knife-edge scanning were more than 50% and 0.8 μm at 41.3 keV, respectively to the FZP with 6-step structure.
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Kazuma MISHIRO, Takanori AOKI, Akio SUZUKI, Tatsuhiko MATSUSHITA, Masa ...2007 Volume 50 Issue 3 Pages 167-169
Published: 2007
Released on J-STAGE: January 01, 2008
JOURNAL FREE ACCESSApproximately 30-nm thick iron films were deposited using an iron target with a high purity of 5 nine on glass or polycarbonate substrate by radio-frequency magnetron sputtering, in order to use for media of the write-once disk. The transmittance change between the as-deposited state and the annealed state (500°C×10 min) was about 18% at the wavelength of 400 nm. For the films on the polycarbonate substrate, the CNR of 42 dB was obtained at a peak power of 8 mW (at λ=406 nm, NA=0.65). On this time, we observe recording pits (diameter of about 0.26 μm) written at the peak power of 10 mW.
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Masato YASUMOTO, Shigeharu TAMURA, Nagao KAMIJO, Akihisa TAKEUCHI, Ken ...2007 Volume 50 Issue 3 Pages 170-172
Published: 2007
Released on J-STAGE: January 01, 2008
JOURNAL FREE ACCESSA one-dimensional multilayer Fresnel zone plate (1D-FZP) is capable to be an optical element for the micro X-ray computer tomography imaging with high spatial resolution. We developed the 1D-FZP with sputtered-sliced method. The 1D-FZP composes of high-Z (Cu) layer and low-Z (Al) layer, alternately. In this study, we fabricated the Cu/Al multilayer on a Si substrate at room temperature and 200°C, respectively. The smooth section of both multilayer was observed with scanning electron microscope.
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Yukiko OKANO, Shuichi TAJIRI, Takashi AOZONO, Akio OKAMOTO, Soichi OGA ...2007 Volume 50 Issue 3 Pages 173-174
Published: 2007
Released on J-STAGE: January 01, 2008
JOURNAL FREE ACCESSThe electric characteristics of TaAl-N thin film were investigated. The resistivity of the TaAl-N thin films, having been prepared by DC reactive sputtering of Ta and Al (8:2 area ratio) target in a gas mixture of argon and nitrogen, showed pressure-ratio dependence of nitrogen (PN2/Ptotal). The condition of high PN2/Ptotal was effective for fabricating the films, having a high TCR (the temperature coefficient of the resistivity). As a result, in the condition of PN2/Ptotal=75%, the TCR values were (-)35000 ppm/°C (at 100°C) and (-)25000 ppm/°C (at 200°C, resistivity).
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Takeshi KIMURA, Akiyoshi NAGATA2007 Volume 50 Issue 3 Pages 175-177
Published: 2007
Released on J-STAGE: January 01, 2008
JOURNAL FREE ACCESSThe power generation characteristic at room temperature of a single chamber fuel cell using a novel hydrated aluminium oxide, pseudoboehmite (pb) proton conductor as the electrolyte was studied based on dependence on the crystal structure and treatment temperature of pb electrolytes generated by the hot water treatment of Al and Al2O3 films evaporated on the glass substrate. A single fuel cell using the pb electrolyte could be fabricated in various gas mixtures of hydrogen and oxygen at room temperature. Maximum open circuit voltage was obtained at a fuel cell using pb electrolytes generated by the soak treatment of Al and Al2O3 films during 4 hours in the hot water of 90°C.
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Atsushi OOWADA, Toshihiko KOJIMA, Mitsuaki TAKEUCHI, Yasuhito GOTOH, M ...2007 Volume 50 Issue 3 Pages 178-180
Published: 2007
Released on J-STAGE: January 01, 2008
JOURNAL FREE ACCESSWe measured current variation of carbonoized silicon-field emitter arrays (Si:C-FEA) in hydrogen (H2) ambient to show durability against hydrogen exposure. We operated both silicon-field emitter arrays (Si-FEA) and Si:C-FEA in H2 atmosphere for 100 hours. Hydrogen gas is one of the major component of total residual pressure in ion implanter. As a result, the emission current from Si-FEA decreased from 20 μA to 8 μA. But the emission current from Si:C-FEA increased from 20 μA to 80 μA. It was shown that the durability of Si:C-FEA against H2 gas was better than that of Si-FEA.
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Seizo MORITA, Yoshiaki SUGIMOTO, Noriaki OOYABU, Óscar CUSTANCE ...2007 Volume 50 Issue 3 Pages 181-183
Published: 2007
Released on J-STAGE: January 01, 2008
JOURNAL FREE ACCESSAn atomic force microscope (AFM) under noncontact and nearcontact regions operated at room-temperature (RT) in ultrahigh vacuum, is used as a tool for topography-based atomic discrimination and atomic-interchange manipulations of two intermixed atomic species on semiconductor surfaces. Noncontact AFM topography based site-specific force curves provide the chemical covalent bonding forces between the tip apex and the atoms at the surface. Here, we introduced an example related to topography-based atomic discrimination using selected Sn and Si adatoms in Sn/Si(111)-(√3 ×√3 ) surface. Recently, under nearcontact region, we found a lateral atom-interchange manipulation phenomenon at RT in Sn/Ge(111)-c(2×8) intermixed sample. This phenomenon can interchange an embedded Sn atom with a neighbor Ge atom at RT. Using the vector scan method under nearcontact region, we constructed “Atom Inlay”, that is, atom letters “Sn” consisted of 19 Sn atoms embedded in Ge(111)-c(2×8) substrate. Using these methods, now we can assemble compound semiconductor nanostructures atom-by-atom.
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Atsushi SUZUKI, Akira KUROKAWA, Hidehiko NONAKA2007 Volume 50 Issue 3 Pages 184-186
Published: 2007
Released on J-STAGE: January 01, 2008
JOURNAL FREE ACCESSOur partial pressure measurement for a binary gas with a quartz sensor can be applied to plasmas. In this study, the Q-sensor outputs, which depend on pressure, molecular weight and viscosity of gases, were compared to the results by gas analysis with a quadrupole mass spectrometer (QMS). For H2 plasmas, the Q-sensor outputs changed when discharges were turned on and off. On the other hand, the results from mass spectroscopy by the QMS showed the degas of carbon monoxide (CO) during the discharges. Since the changes of the Q-sensor outputs correspond to the CO production above, it can be concluded that the Q-sensor measurements can detect the gas composition changes in the plasmas, thereby, can be used as a simple gas analysis method compared to a conventional mass spectrometer.
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Yuji TORIKAI, Shogo NAOE, Kenya AKAISHI, Kuniaki WATANABE, Masao MATSU ...2007 Volume 50 Issue 3 Pages 187-189
Published: 2007
Released on J-STAGE: January 01, 2008
JOURNAL FREE ACCESSTo understand the release mechanism of tritium from solid materials, release rate of tritium was measured when a tritium loaded 316 stainless steel specimen was put in dry argon gas flow of atmospheric pressure at room temperature. During blowing of argon gas released products from the specimen were collected in water bubblers which were set in the downstream of the blowing circuit, and the tritium content in the bubbler water was periodically measured as a function of time by scintillation counter. More than 99% of released species from the specimen was tritiated water, HTO. The measured result of tritium release rate showed that tritium is released chronically for a long time. The chronic release rate of tritium was evaluated using the diffusion model reported by Calder and Lewin, and it was found that when a reasonable value for the bulk diffusion coefficient of tritium is assumed, the tritium release rate can be described with the diffusion flux at the surface boundary of the specimen.
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Munetaka SONOBE, Hiroshi MURAKAMI, Tsukasa YAMASHITA, Hitoshi NAKAI, T ...2007 Volume 50 Issue 3 Pages 190-192
Published: 2007
Released on J-STAGE: January 01, 2008
JOURNAL FREE ACCESSWe proposed the cold cathode made of carbon nanotubes (CNTs) for an ionization gauge.
The CNTs were grown radially on a Ni wire by DC-plasma chemical vapor deposition (CVD). The radial growth of CNTs was obtained by controlling deposition temperature, C2H2: NH3 ratio and pressure. Pre-heating of the Ni wire in vacuum prior to CVD process resulted in the higher density of CNTs. The field emission characteristics of two types of CNT cathodes were examined.
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Yoshiro KUSUMOTO2007 Volume 50 Issue 3 Pages 193-195
Published: 2007
Released on J-STAGE: January 01, 2008
JOURNAL FREE ACCESSMolecular flow symmetry in an adsorbent and arbitrarily shaped pipe is mathematically considered based on the diffuse and the beam reflection models. In the previous papers, it was shown that there are innumerable reflection rules preserving the flow symmetry, provided that the molecular flux is conserved in a collision with the pipe wall. When the mass conservation does not hold (i.e. the pipe wall is adsorbent), there remain only five symmetry-preserving reflection rules, which are characterized by time reversibility as well as space isotropy.
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Yuzo JOHDAI, Yuto YOSHIIWA, Takahiko NURUKI, Shintaro NAKAMURA, Tomono ...2007 Volume 50 Issue 3 Pages 196-198
Published: 2007
Released on J-STAGE: January 01, 2008
JOURNAL FREE ACCESSThe reaction dynamics of the Bi-line structure (BLS) with copper-phthalocyanine (CuPc) molecules have been investigated by scanning tunneling microscopy. Bi atoms deposited on the Si(100) surface at 400-500°C, form one-dimensional wires consisting of two chains of Bi dimers in the topmost layer. When CuPc molecules were deposited on the Si(100) surface with the BLSs at room temperature, we observed bright 4-spot shapes and c(4×4) structures in the terraces. When the surface was annealed at 200°C, the bright 4-spot disappeared and the area with c(4×4) periodicity increased. The CuPc molecules, adsorbed on BLSs, were dissociated by catalytic reaction of Bi atoms.
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Akira KUROKAWA, Kenji Odaka, Tosiyuki FUJIMOTO, Yasushi AZUMA2007 Volume 50 Issue 3 Pages 199-201
Published: 2007
Released on J-STAGE: January 01, 2008
JOURNAL FREE ACCESSTo develop nanometric film thickness standard (FTSs), uniformity of silicon dioxide thin film were investigated by X-ray Reflectometry (XRR). The samples we investigated were thermally grown oxides (O2-Oxides) and ozone-formed oxide(Ozone-Oxide). The O2-oxide were grown on Si(100) substrate at 1000°C and at 700°C. The Ozone-Oxide was grown at 750°C with the highly concentrated ozone gas. With XRR method the bulk-layer density of oxide films were analyzed for; the O2-Oxide formed at 700°C (D700), the O2-Oxide formed at 1000°C(D1000), and the Ozone-Oxide formed at 750°C (Dozone750). We also analyzed the transition-layer density of the O2-Oxide formed at 700°C (DTL700). The results showed the relation was D1000<Dozone750<D700<DTL700. The result indicated that Ozone-Oxide is suitable to produce the FTSs which demands the homogeneous density in SiO2 thin film, and also indicated that the density of Ozone-Oxide corresponded to that of O2-Oxide with much higher substrate temperature.
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Keiko ONISHI, Daisuke FUJITA2007 Volume 50 Issue 3 Pages 202-204
Published: 2007
Released on J-STAGE: January 01, 2008
JOURNAL FREE ACCESSWe have demonstrated a novel lithography method by electron-beam enhanced sputtering on a SiO2 thin film formed on a Si(001) substrate using scanning Auger microscopy (SAM) and atomic force microscopy (AFM). SAM analysis suggests that the sputtering rate in the region irradiated by an energetic electron beam with a certain amount of electron dose is found to be significantly enhanced. By combining a scanned electron beam with a nearly homogeneous Ar+ ion sputtering, it has been discovered that the beam-irradiated area are selectively more etched than non-irradiated regions. The mechanism is considered that oxygen-deficient SiOx (x<2) regions formed by electron beam irradiation are relatively unstable against ion sputtering and has higher etching probability than area without beam irradiation.
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Sakae S. INAYOSHI, Fumiaki ISHIGURE2007 Volume 50 Issue 3 Pages 205-207
Published: 2007
Released on J-STAGE: January 01, 2008
JOURNAL FREE ACCESSMicro-arc oxidation (MAO) is an anodizing technique applied to valve metals. With MAO, a crystalline aluminum oxide layer can be grown on aluminum alloys. This paper examines MAO as a surface treatment for metals for vacuum use. A 17.6 μm-thick MAO layer was grown on an A5052 aluminum alloy surface employing 50 Hz AC and a maximum of 450 V. This oxide layer contained α-alumina and γ-alumina crystalline aluminum oxide, and actually consisted of two distinct layers: first, a dense layer about 500 nm thick directly on the substrate, and, second, a 17 μm-thick layer on the dense layer which included numerous voids, each about 10 μm in size. Neither layer had the fine pores - 20-30 nm-structures - exhibited by alumite film. The outgassing rate of a MAO-treated A5052 sample after 10 hours of evacuation was 1.0×10-5 Pa•m3•s-1•m-2, i.e., 1/30 that of alumite with sulfuric acid. The most dominant gas species was water. The MAO sample's corrosion resistance to hydrochloric acid was the same as that of an alumite sample.
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Naoto KAMEDA, Tetsuya NISHIGUCHI, Yoshiki MORIKAWA, Mitsuru KEKURA, Hi ...2007 Volume 50 Issue 3 Pages 208-210
Published: 2007
Released on J-STAGE: January 01, 2008
JOURNAL FREE ACCESSWe have grown SiO2 film on the polycrystalline Si layer using excited ozone gas, which is produced by ultra-violet light irradiation to ozone gas, and characterized the electric properties of the SiO2 film at the MIS capacitor configuration. Even at room temperature, the SiO2 of ~8.5 nm thick can be grown in 60 min. on 1.5×1.5 cm2 poly-Si chips. The leakage current density across the SiO2 film was well fitted to the F-N tunnel current over 6 MV/cm and the breakdown occurred at above 12 MV/cm showing that the film properties satisfy the device quality. The oxidation rate of Si by the excited ozone gas did not show difference on between Si(100) and Si(111) wafers. These results indicate that excited ozone gas can form homogenous SiO2 film on the poly-silicon layer with grains with various silicon crystal orientations at the surfaces.
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Suguru MOTOTANI, Shizuyasu OCHIAI, Sawa GORO, Yoshiyuki UCHIDA, Asao O ...2007 Volume 50 Issue 3 Pages 211-213
Published: 2007
Released on J-STAGE: January 01, 2008
JOURNAL FREE ACCESSHighly ordered nano-crystals formed with vanadylphthalocyanine molecules deposited on KBr substrate by molecular beam epitaxy instrument have been found under certain preparatory conditions. Highly ordered nano-crystals have potential applications in nanotechnology such as nano-transistors and nano-optical switches. In this study, the mechanism and growing process of nano-crystals on KBr substrate were investigated by varying the thermal annealing temperature of the thin film formed by vanadylphthalocyanine (VOPc) molecules deposited on KBr substrate. In VOPc molecules deposited on KBr substrate and thermally annealed with 150°C, highly oriented and aligned nano-crystals were formed on KBr substrate. This indicates that when VOPc molecules thermally diffuse and VOPc grains merge on KBr substrate with treatment, highly oriented and aligned nano-crystals are formed on KBr substrate.
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Norikazu SASAKI, Kentaro OKAMURA, Takeshi KIMURA, Akiyoshi NAGATA2007 Volume 50 Issue 3 Pages 214-216
Published: 2007
Released on J-STAGE: January 01, 2008
JOURNAL FREE ACCESSStack characteristic of solid oxide fuel cell (SOFC) having yttria-stabilized zirconia (YSZ) electrolyte film has been studied on the operating property until lower temperature of 770°C. The YSZ electrolyte film was grown on the Ni-YSZ cermet substrate using as fuel electrode by the RF magnetron sputtering, Terminal voltage of a single cell decreased as lowering the operating temperature. In two parallel cells, the cell resistance reduced to half value and the load current became larger, as compared with the property of a single cell. As a result, it was confirmed that the compact cell stack of thin SOFC improved well the power generation characteristic at middle operating temperature of 770°C.
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Kiyohiro HINE, Satoru YOSHIMURA, Masato KIUCHI, Satoshi HAMAGUCHI2007 Volume 50 Issue 3 Pages 217-219
Published: 2007
Released on J-STAGE: January 01, 2008
JOURNAL FREE ACCESSThe Au sputtering yields by Ne ions were measured in the range of low injection energy with a low-energy mass analyzed ion beam system. For the ion beam characterization, the mass and energy spectra of the Ne ion beams were measured with a plasma process monitor (Balzers, PPM421) and it was found the Ne beams were essentially monochromatic. The ion beam was injected into an Au thin film prepared on a quartz crystal microbalance (QCM) and its sputtering yield was evaluated from the Au mass decrement. It has been found that the measured Au sputtering yields by Ne ion beams in the energy range of 100-200 eV approximately agree with the previously reported corresponding values. The sputtering yields were also measured for the injection energies below 100 eV. The threshold energy for Au sputtering by Ne estimated from the low energy data is 35 eV.
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Ohko MAKITA, Shoji TAKAGI, Tetsuji GOTOH2007 Volume 50 Issue 3 Pages 220-222
Published: 2007
Released on J-STAGE: January 01, 2008
JOURNAL FREE ACCESSHydroxylation on cleaved MgO(001) surface by water exposure has been studied using X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The used samples are MgO surfaces cleaved in air, exposed to water vapor and immersed in water. The immersed times are 0.01, 0.03, 0.1, 0.3, 1 and 3 h. Water molecules could not be found in the XPS spectra of all samples. Hydroxyl exists on the surface immediately after cleaved in air. The hydroxyl component in the XPS spectra becomes large with the immersed time up to 0.03 h. At the 0.1 h of the immersed time the component of Mg(OH)2 appears in the XPS spectrum and the component becomes larger with the immersed time. These results indicate that the hydroxylation makes progress by dissociative adsorption of water right after cleavage in air and the Mg(OH)2 component begin to grow from about 0.1 h of the immersed time.
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