研究者業績
  1. 研究者検索結果一覧
  2. 青木 孝憲

青木 孝憲

アオキ タカノリ  (Takanori Aoki)

基本情報

所属
大阪産業大学 工学部電気電子情報工学科 講師
学位
工学士(大阪産業大学)
研究者番号
40268280
J-GLOBAL ID
200901021141928991
researchmap会員ID
5000043904

研究分野

 2

学歴

 1

論文

 77
  • 日本真空協会論文誌『真空』 Vol.45(No.3(2002)) 247-250 2002年3月  
    本論文は酸化物のZnOとIn203をターゲットとし、パルスレーザー堆積法でDVD－R基板に成膜し、その光ディスク特性について詳しく述べている。それぞれのターゲットのトレース比を最適値に設定し、最適組成のディスクを作製し、ブルーレーザー（波長406nm）の光ディスク回転評価装置で記録特性を測定し、成膜条件を最適化したときCNR＝50dB以上の良好な値が得られ、次世代の短短波長対応光ディスクに応用できることを見出した。
  • Takanori Aoki, Shin Akiduki, Akio Suzuki, Tatsuhiko Matsushita, Masahiro Okuda
    Shinku/Journal of the Vacuum Society of Japan 45(3) 247-250 2002年  査読有り
    Thin films (of 50 nm thick) with a stacked structure (of 10∼150 layers) of In2O3 and ZnO have been deposited onto the glass and the polycarbonate substrates using the split target consisting of In2O3 and ZnO by a pulsed laser technique with an ArF excimer laser. A relation of the transmittance change ΔT at the wavelength of 400 nm between the annealed state (480°C × 20 min) and the as-deposited state versus the number of layers for the structure fabricated at the trace ratio of In2O3:ZnO = 1:1 was obtained. The structure with 20 layers showed the maximal value of ΔT. SEM observation revealed that the surfaces of these films were enough smooth to use in static or revolution tests for 'write'. AFM observation showed that surface roughness of the as-deposited state and the annealed state were Ra of 0.76 nm and Ra of 2.25 nm respectively. A peak power dependence of CNR of 3T signal (λ = 406 nm, NA = 0.65) at a linear velocity of 5 m/s and a read power of 0.6 mW was measured for the disk samples with 60-layers fabricated for the revolution tests. That the write power of less than 3 mW was required and maximal value of CNR = 67 dB was obtained. The values of CNR could be improved by optimizing the number of layers and the film compositions.
  • Thin Solid Films (Vol.411) Issue1,PP,23-27 2002年  
  • 日本真空協会「真空」 Vol.45 No.3 PP.247-250 2002年  
  • The Solid Films (Vol.411) Issue1,PP,23-27 2002年  
  • A Suzuki, T Matsushita, T Aoki, Y Yoneyama, M Okuda
    JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS 40(4B) L401-L403 2001年4月  
    In2O3 doped with 5 wt% SnO2 (indium-tin oxide(ITO)(5 wt%)) films have been deposited on glass and quartz substrates in a magnetic field generated from three pieces of rare-earth permanent magnets (1.25 T flux density) placed at every 120 degrees angle to surround the plume produced by pulsed laser deposition using an ArF laser (lambda = 193 nm). In all experiments, a repetition rate of 10 Hz, an energy density of 1.5 J/cm(2), and an irradiation time of 20-30 min (12000-18000 shots) were used. The lowest resistivity of 7.2 x 10(-5) Omega -cm and an optical transmittance of more than 90% in the visible region of the spectrum were obtained for approximately 30-nm-thick ITO (5 wt%) films deposited at a substrate temperature of 300 degreesC in oxygen with a flow rate of 2 seem. Very smooth surfaces with an average surface roughness of 0.61 nm were observed by scanning electron microscope (SEM) and atomic force microscope (AFM).
  • A Suzuki, T Matsushita, T Aoki, Y Yoneyama, M Okuda
    JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS 40(4B) L401-L403 2001年4月  
    In2O3 doped with 5 wt% SnO2 (indium-tin oxide(ITO)(5 wt%)) films have been deposited on glass and quartz substrates in a magnetic field generated from three pieces of rare-earth permanent magnets (1.25 T flux density) placed at every 120 degrees angle to surround the plume produced by pulsed laser deposition using an ArF laser (lambda = 193 nm). In all experiments, a repetition rate of 10 Hz, an energy density of 1.5 J/cm(2), and an irradiation time of 20-30 min (12000-18000 shots) were used. The lowest resistivity of 7.2 x 10(-5) Omega -cm and an optical transmittance of more than 90% in the visible region of the spectrum were obtained for approximately 30-nm-thick ITO (5 wt%) films deposited at a substrate temperature of 300 degreesC in oxygen with a flow rate of 2 seem. Very smooth surfaces with an average surface roughness of 0.61 nm were observed by scanning electron microscope (SEM) and atomic force microscope (AFM).
  • 日本真空協会論文誌『真空』 Vol.44(No.3(2001)) 373 2001年3月  
    本論文は酸化物のZnOとIn?0?ターゲットをスプリットにして用いArFエキシマレーザーを用いたパルスレーザー堆積法で積層した光記録膜を作製しその基礎的特性について述べている。全体の膜厚を100nm前後にし積層数を100～200層にしたとき、ZnOとIn?0?のレーザートレース比を9：1で、as depositedと熱処理（400～450℃）したときの透過率差△Tが最も大きくなり、Nd：YAGパルスレーザーの第二高調波（波長355nm、3ns）で直径1μm程度の記録ドットが明確に書き込むことができ短波長対応の高密度光記録膜として機能することを見出した。
  • 日本真空協会論文誌『真空』 Vol.44(No.3(2001)) 374 2001年3月  
    本論文は金属ZnおよびInと酸化物のGa?0?を高周波スパッタリング法で多層に積層し、as depo時とアニール後の透過率変化について詳しく述べている。積層数が200から300層で波長400nm前後で最も大きな透過率差△T＝70％以上の値が得られ、大きなCNRが得られる光記録膜が可能であることを見出した。Nd：YAGレーザーを使用した静止型の書き込み装置で第二高調波（355nm）で1μm前後のドットが書き込めることを確認した。
  • 日本真空協会論文誌『真空』 Vol.44(No.3(2001)) 244-247 2001年3月  
    本論文は基板側に自公転ジグを装備した高周波スパッタリングで金属Inと酸化物のZnOおよびGa?0?をターゲットとし、DVD－R基板に同時スパッタし、その光でディスク特性について詳しく述べている。それぞれのターゲットの高周波電力を最適値に設定し、最適組成のディスクを作製し、ブルーレーザー（波長406nm）の光ディスク回転評価装置で記録特性を測定し、CNR＝45～50dBの良好な値が得られ、次世代の短波長対応光ディスクに応用できることを見出した。
  • 日本真空協会論文誌『真空』 第43巻(第3号) 292-295 2000年3月  
    高周波スパッタリング法を用いて金属インジウムと酸化ガリウムを同時放電させGa－In系薄膜を作製した場合、近紫外領域で動作する高密度光記録膜が得られる。それぞれのRF出力を60Wおよび150Wで成膜したとき、as depo．とアニール時の透過率差が波長350nmで70％の大きな値が得られ、Nd：YAG レーザーの第3高調波（355nm）のパルス光では直径約0.8μmのドットが書き込めることが分かった。
  • Takanori Aoki, Akio Suzuki, Tatsuhiko Matsushita, Masahiro Okuda
    Shinku/Journal of the Vacuum Society of Japan 43(3) 292-295 2000年  査読有り
    Thin films of Ga-In oxide (approx. 150 nm) have been deposited on glass substrate at room temperature by radio-frequency (rf) magnetron sputtering with two targets of Ga2O3 and metallic In, on which rf-powers of 150 W and 60-80 W were added respectively. In the oxide films prepared by this method, the difference in the transmittance, ΔT, between the as-deposited state and the annealed state (400°C × 10 min) was more than 70% in the wavelength region of 350-600 nm and at the wavelength of 320 nm, the value of ΔT of 42% was obtained. It was found from XRD spectra that (1) the In (101) peak was found in the as-deposited state (colored state) and (2) the In2O3(222) peak was formed in the annealed state (transparent state). It was recognized from XPS measurement that the phase transition between the as deposited state and the annealed state well corresponded to the transition of In (colored state)→In2O3 (transparent state). The ability to record on these oxide films without protection layer, using THG of Nd: YAG laser (δ=355 nm, 3 ns) was confirmed. These results will be useful for highly sensitive optical recording films with high density in the ultraviolet-blue wavelength region.
  • Akio Suzuki, Masanari Furiki, Takanori Aoki, Tatsuhiko Matsushita, Masahiro Okuda
    Shinku/Journal of the Vacuum Society of Japan 43(3) 268-272 2000年  査読有り
    There are many unsettled questions for transparent conducting ITO thin films if used as electronic devices: expensive and weak in durability to reduction gas. In order to improve these disadvantageous points, AZO (ZnO:Al2O3) was deposited on the ITO layer by PLD method and laminated transparent conducting films with a structure of ITO + AZO were prepared. It was found that if the film thickness of the upper AZO layer increased, the sheet resistance decreased. At the same time, the increase of averaged transmittance in the visible wavelength region (400-700 nm) due to an anti-reflection effect caused by two layer structure of ITO + AZO was recognized. Moreover, it was found from SEM and AFM observations that the surface randomness was improved from 4.54 nm for the ITO single layer to 2.89 nm for the ITO + AZO (120 nm) structure.
  • Akio Suzuki, Yoshitaka Yoneyama, Takanori Aoki, Tatsuhiko Matsushita, Masahiro Okuda
    Shinku/Journal of the Vacuum Society of Japan 43(5) 611-615 2000年  査読有り
    The pulsed laser deposition (PLD) method has furnished useful means to fabricate films with noble and highly efficient properties. However, when the equipment with an excimer laser of intricate and expensive features is used to fabricate the films, it will bring about the raising of cost. Therefore, we paid attention to the PLD method by Nd:YAG laser with simple and inexpensive features and performed to prepare films in magnetic fields using Nd:YAG laser (fundamental 1064 nm and SHG 532 nm), in which it was aimed to suppress the generation of droplet and to shorten the preparation time. From these results, it was confirmed that by preparing in the magnetic field, it was able to fabricate the films with properties of low resistivity and high transparency. Moreover, from XRD measurements and SEM observation, the reforming of surface morphology due to improvement in crystallinity, was found. These effects were remarkable in the films prepared using the wavelength of 532 nm.
  • M Okuda, T Aoki, A Suzuki, T Matsushita
    FIFTH INTERNATIONAL SYMPOSIUM ON OPTICAL STORAGE (ISOS 2000) 4085 96-103 2000年  
    The targe transmittance change induced Zn-Ga-In oxide films grown by the sputtering method was investigated in the wavelength near 400 nm. The ability to record on the Zn-Ga-In oxide films, using THG of YAG laser (lambda = 355 nm, 3 ns) was confirmed.
  • M Okuda, T Aoki, A Suzuki, T Matsushita
    FIFTH INTERNATIONAL SYMPOSIUM ON OPTICAL STORAGE (ISOS 2000) 4085 96-103 2000年  
    The targe transmittance change induced Zn-Ga-In oxide films grown by the sputtering method was investigated in the wavelength near 400 nm. The ability to record on the Zn-Ga-In oxide films, using THG of YAG laser (lambda = 355 nm, 3 ns) was confirmed.
  • M Okuda, T Aoki, A Suzuki, T Matsushita
    FIFTH INTERNATIONAL SYMPOSIUM ON OPTICAL STORAGE (ISOS 2000) 4085 96-103 2000年  
    The targe transmittance change induced Zn-Ga-In oxide films grown by the sputtering method was investigated in the wavelength near 400 nm. The ability to record on the Zn-Ga-In oxide films, using THG of YAG laser (lambda = 355 nm, 3 ns) was confirmed.
  • T Aoki, A Suzuki, T Matsushita, H Kaimi, M Okuda
    JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS 38(8) 4802-4803 1999年8月  
    Thin films (d = 120-150 nm) with a laminated structure of Ga2O3 and In2O3 have been deposited using the split target constructed of Ga2O3 and In2O3 by a pulsed laser deposition technique with an ArF laser. The transmittance change between the as-deposited and the annealed states for the film with the trace ratio of Ga : In = 3 : 1 (the weight percent ratio of Ga : In = 5.5 : 1) was 65 % at the wavelength of 350 nm.
  • 日本真空協会論文誌『真空』 第42巻(3号) 1999年3月  
  • 青木 孝憲, 戸田 昌吾, 鈴木 晶雄, 松下 辰彦, 奥田 昌宏
    日本真空協会論文誌『真空』 第42巻(3号) 469-469 1999年3月  
  • 青木 孝憲, 浜路 和昭, 鈴木 晶雄, 松下 辰彦, 奥田 昌宏
    日本真空協会論文誌『真空』 第42巻(3号) 470-470 1999年3月  
  • 日本真空協会論文誌『真空』 第42巻(3号) 1999年3月  
  • Takanori Aoki, Hideki Kaimi, Akio Suzuki, Tatsuhiko Matsushita, Masahiro Okuda
    Shinku/Journal of the Vacuum Society of Japan 42(3) 317-320 1999年  査読有り
    Thin films of Ga-In oxide (approximately 100 nm) have been deposited, at an Ar pressure of 4 Pa, on glass substrate at room temperature by radio-frequency (rf) magnetron sputtering with two targets of Ga2O3 and metallic In, on which rf-power of 150 W and 60 W were added respectively. In the oxide films prepared by this method, the difference in the transmittance, ΔT, between the annealed (300 °C×10 min) and the as-deposited state was more than 60% in the wavelength region of 350 to approximately 600 nm. It was found from XRD spectra that (1) the In (101) peak was formed in the as-deposited state (colored state) and (2) the In2O3 (222) peak was formed in the annealed state (transparent state). The ability to record on these oxide films without protection layer, using THG of Nd:YAG laser (λ = 355 nm, 3 ns) was confirmed. These results will be useful for highly sensitive optical recording films with high density in the ultraviolet-blue wavelength region.
  • Takanori Aoki, Hideki Kaimi, Akio Suzuki, Tatsuhiko Matsushita, Masahiro Okuda
    Shinku/Journal of the Vacuum Society of Japan 42(3) 313-316 1999年  査読有り
    The Ga-In oxide films (100 to approximately 150 nm) have been deposited on glass and quartz substrates by irradiating the pulsed laser beam of an ArF laser (λ = 193 nm) on the split target composed of Ga2O3 and In2O3 (99.999% purity). In all experiments, a repetition rate of 10 Hz, an energy density of 0.4 J/cm2, an irradiation time of 12-15 min (7200-9000 shots) and a target-to-substrate distance of 4 cm were used. It was found from optical spectra that for the Ga-In oxide films prepared with a moved distance of Ga2O3:In2O3 = 3:1 on the split target, there was a difference in the transmittance of greater than 66% near 350 nm wavelength, between the annealed (transparent, Egopt 4.2 eV) and the as-deposited state (opaque, Egopt = 2.0 eV). The ability to record on the Ga-In oxide films without a protection layer, using THG of Nd:YAG (λ = 355 nm, 3 ns) was confirmed. These results will be useful for highly sensitive optical recording films with high density in the ultraviolet-blue wavelength region.
  • 日本真空協会論文誌『真空』 第41巻 279 1998年3月  
  • 日本真空協会論文誌『真空』 第41巻(3月号) 280-281 1998年3月  
  • Akio Suzuki, Hiroshi Yamanishi, Daisuke Tanaka, Takanori Aoki, Tatsuhiko Matsushita, Masahiro Okuda
    Shinku/Journal of the Vacuum Society of Japan 41(3) 266-269 1998年  査読有り
    The 100∼200nm-thick ZnO:M (M = Ga2O3, In2O3, Al2O3, Ag2O, CuO and SnO2) films in which droplet formation was suppressed have been deposited on glass substrates at room temperature by a pulsed laser deposition technique using SHG of Nd:YAG laser (λ = 532 nm). Transmittance in the as-deposited state of ZnO:Ga2O3 (2 wt%) film was the smallest among all the ZnO:M films: the film was colored with dark brown. When the films were annealed at 390°C for 50 min, the transmittance of the films increased markedly. The difference in the transmittance between the asdeposited state and the annealed state ΔT was 76% at the wavelength of 400 nm. It was found that maximal transmittance difference ΔTmax was 91% at the wavelength of 472 nm. From XRD spectra, the coloring phenomenon was explained from the fact that the Zn (100) and Zn (101) peaks were present in the as-deposited state and absent in the annealed state, and ZnO peaks such as (200), (101) and (100) were present in the annealed state and absent in the asdeposited state. It is thought that the ZnO doped with Ga2O3 films are useful as a high density optical memory due to the short wavelength (400 nm) of the next generation.

MISC

 6
  • Naoya ICHII, Toshimichi KAMINISHI, Takanori AOKI, Tatsuhiko MATSUSHITA, Akio SUZUKI, Masahiro OKUDA
    The 21th Symposium on Phase Change Optical Information Strage PCOS 2009 2009年11月  査読有り
  • Takanori AOKI, Akio SUZUKI, Kazuma MISHIRO, Tatsuhiko MATSUSHITA, Masahiro OKUDA
    The 21th Symposium on Phase Change Optical Information Storage PCOS 2008 3-8 2008年11月  査読有り
  • Kazuma MISHIRO, Takanori AOKI, Tatsuhiko MAtsushita, Akio SUZUKI, Masahiro OKUDA
    Proceedings of the 19th Symposium on Phase Change Optical Information Storage PCOS 2007 21-26 2007年11月  査読有り
  • 安倉 秀明, 青木 孝憲, 鈴木 晶雄, 松下 辰彦, 奥田 昌宏
    電気学会論文誌． Ｃ 125(11) 1641-1645 2005年  
    Approximately 150 nm-thick Al-doped zinc oxide (AZO) films with c-axis orientation have been prepared on glass substrates by pulsed laser deposition (PLD) using a split target divided into AZO(Al2O3 : 1 wt.%) and AZO(Al2O3 : 2 wt.%), which resulted in the adjustment of film composition by changing the ratio (trace ratio) of the time required to irradiate each side of the target alternately by an ArF excimer laser (λ= 193 nm). The film deposition took place at a substrate temperature of 230 °C. The trace ratio of 1 : 1 was employed, resulting in the film component of AZO(Al2O3 : 1.5 wt.%). In order to improve the film flatness, D.C. voltage of 150 V was applied perpendicularly to the plume generated between the substrate and the target. As a results, fluctuation of film-thickness improved from 7.8 % for the case without applied voltage to 4.7 %, with applied voltage of 150 V. For the AZO film deposited by irradiating a pulsed laser beam of energy density of 1 J/cm2 at repetition frequency of 10 Hz, the lowest resistivity was 2.47×10-4 Ω·cm for the case without applied voltage and 2.59×10-4 Ω·cm with applied voltage of 150 V. An average transmittance of more than 85 % in the visible range were obtained for the AZO films fabricated with and without D.C. voltage of 150 V applied perpendicularly to the plume, providing useful functionality as TCO films in the visible range.
  • 安井 光弘, 青木 孝憲, 鈴木 晶雄, 松下 辰彦, 奥田 昌宏
    電気学会論文誌C 124巻, 11号, 2202-2207(11) 2202-2207 2004年  
    β-FeSi2 thin films were grown on Si(111) substrates by pulsed laser deposition (PLD) method using Nd: YAG Laser (λ = 1064 nm, laser energy = 50 mJ, laser energy density = 1.65 J/cm2, repetition frequency = 10 Hz). In the fabrication process, three targets of (a) Fe(5N), (b) FeSi2(3N) and (c) Fe(5N) + FeSi2(3N) were used. The β-FeSi2 thin films having best properties of crystallinity were obtained in the case of (c), in which the first layer as the template was formed with the target of Fe(5N) and then, on top of that, the second layer was deposited with the target of FeSi2(3N). At this time, it was found that by XRD measurement, the degree of crystallinity of the films of the case (c) in which the first layer was introduced as the template improved 1.4 times as much as compared with the case (a), and that by SEM and AFM observations, surface morphologies also improved. Moreover, it was found that by TEM obeservation, the β-FeSi2 thin grew uniformly along the direction of (220) or (202) from the interface of the Si substrate and the film to the free surface and that by EDS analysis, the compositions of Fe and Si were uniformly distributed.
もっとみる

所属学協会

 4

共同研究・競争的資金等の研究課題

 1

研究テーマ

 2
  • 研究テーマ
    酸化物光記録膜に関する研究
    キーワード
    酸化物、光記録膜
  • 研究テーマ
    透明導電膜に関する研究
    キーワード
    ZnO
    概要
    PLD法を用いてZnO系透明導電膜を作成し、低抵抗かつ高透光性を示す材料および成膜手法を開発する。
一覧へ戻る