掲載種別：研究論文（学術雑誌）  

DOI： 10.1039/d1ja00164g

DOI： 10.35848/1347-4065/ab8b3e

掲載種別：研究論文（学術雑誌）  

<p>We studied a pumpdown curve in the low and medium vacuum regimes for a conductance-limited pumping. Senda [H. Senda, SEI Technical Review <b>176</b>, 1 (2010).] predicted that the exponential decrease of the chamber pressure, followed by the reciprocal behavior with time near the lower limit of the viscous flow. He proposed a pressure boundary between the exponential decrease and the reciprocal decrease as a "Bifurcation pressure". We experimentally found bifurcation pressures and they quantitatively compered with the theoretical estimation. The result of our experiment agreed fairly well with values that had been obtained by the theoretical calculation.</p>

DOI： 10.1380/vss.61.292

CiNii Article

掲載種別：研究論文（学術雑誌）   共著区分：共著  

DOI： 10.1380/ejssnt.2017.96

掲載種別：研究論文（学術雑誌）  

Initial silicide formation on a Ni(110) surface was studied by scanning tunneling microscopy (STM) in an ultrahigh vacuum. Less than 0.5 ML of Si deposition initiated a Si-Ni mixed layer by displacing substrate Ni, and dark sites were formed in the STM images. A 0.5 ML-Si deposited surface showed that Si and Ni were alternately aligned in a close-packed [11¯0] row whereas Si pairs aligned along the [001] direction forming p(1×2), obliquely aligned forming c(2×2), or even straightly-and-obliquely aligned forming c(4×2) superstructures. A first-principles total energy calculation showed that the p(1×2) and c(4×2) structures had almost the same energy while the c(2×2) structure gave 13 meV/1×1 higher energy. Because a Si-Si bond in the close-packed [11¯0] row is energetically unfavorable, Si deposition of more than 0.5 ML did not further replace the substrate Ni, but silicide islands were nucleated along with a trench structure.

DOI： 10.1016/j.susc.2017.01.003

掲載種別：研究論文（学術雑誌）  

CuとNiはバルクで全率固溶体を作るが、混合エネルギーが正であるため、相分離することが予想されている。<br> 本発表では、Ni(110)表面上にCu-Niの２次元合金を作製し、STMで構造相関を測定したところ、[1 -1 0]方向にのみ正の相関があることを見出し、Ising模型と比較することによって相互作用エネルギーを導出した。

DOI： 10.14886/sssj2008.37.0_124

CiNii Article

掲載種別：研究論文（学術雑誌）  

通常、排気方程式は一定の実効排気速度を仮定して計算されるが、粘性流領域ではコンダクタンスが配管出入り口の平均圧力に比例するため、真空容器と真空ポンプとの間のコンダクタンスが小さい場合 、容器内の圧力は指数関数的には変化せず、ある圧力から時間の逆数で圧力が低下する領域がある。配管のコンダクタンスの圧力依存性を含んだ排気方程式の解析解と実験で得られた排気曲線を比較した結果、比較的良い一致を示した。

DOI： 10.14886/sssj2008.37.0_266

CiNii Article

掲載種別：研究論文（学術雑誌）  

通常、排気方程式は一定の実効排気速度を仮定して計算されるが、粘性流領域ではコンダクタンスが配管出入り口の平均圧力に比例するため、真空容器と真空ポンプとの間のコンダクタンスが小さい場合 、容器内の圧力は指数関数的には変化せず、ある圧力から時間の逆数で圧力が低下する領域がある。配管のコンダクタンスの圧力依存性を含んだ排気方程式の解析解と実験で得られた排気曲線を比較した結果、比較的良い一致を示した。

DOI： 10.14886/sssj2008.37.0_266

CiNii Article

掲載種別：研究論文（学術雑誌）  

CuとNiはバルクで全率固溶体を作るが、混合エネルギーが正であるため、相分離することが予想されている。<br> 本発表では、Ni(110)表面上にCu-Niの２次元合金を作製し、STMで構造相関を測定したところ、[1 -1 0]方向にのみ正の相関があることを見出し、Ising模型と比較することによって相互作用エネルギーを導出した。

DOI： 10.14886/sssj2008.37.0_124

CiNii Article

掲載種別：研究論文（学術雑誌）  

<p>First-principles total energy calculations were performed to investigate stable atomic structures for the displacive adsorption of silicon on the Ni(110) surface. Gibbs free energies were compared for 0-4 silicon atoms embedded into the top layer in a 2×2 unit for the Ni(110) surface. When a half monolayer of Si was embedded, the p(1×2) structure had the lowest energy, and the c(2×2) structure had only 13 meV/1×1 higher energy than the p(1×2) structure. By extending to a 4×2 unit, the c(4×2) structures had almost the same energy with the p(1×2) structure. Alternating Si-Ni chains along the close-packed [1-10] row play an essential role to stabilize these structures. Si and Ni are alternatively aligned in separate [1-10] rows forming a p(2×1) structure, which had 276 meV/1 1 higher energy than the p(1×2) structure. For the p(2×1) structure, unique one-dimensional electronic bands derived by the Si-3<i>s</i> states were formed along the [1-10] direction. [DOI: 10.1380/ejssnt.2017.96]</p>

DOI： 10.1380/ejssnt.2017.96

CiNii Article

掲載種別：研究論文（学術雑誌）  

Ni(111)、(100)、(110)表面でのSi吸着後形成されるシリサイド構造を超高真空下でSTM観察を行った。Ni(111)表面では、Siが1/3ML吸着したroot-3構造が安定構造であり、Ni(100)表面では1/2MLのroot-2構造、Ni(110)表面では1/2MLのp(1x2)、c(2x2)、c(4x2)構造が共存することが分かった。

DOI： 10.14886/sssj2008.36.0_411

CiNii Article

掲載種別：研究論文（学術雑誌）  

フレキシブルエレクトロニクスに向けてプラスチック基板への電極材料の製膜は重要な要素技術である。本発表では、PEN（=Polyethylene naphthalate)基板上へのITO薄膜の製膜条件を最適化し、膜厚100 nmで<10^-3 Ohm cmの低抵抗ITO薄膜を形成できたので報告する。

DOI： 10.14886/sssj2008.36.0_132

CiNii Article

掲載種別：研究論文（学術雑誌）  

フレキシブルエレクトロニクスに向けてプラスチック基板への電極材料の製膜は重要な要素技術である。本発表では、PEN（=Polyethylene naphthalate)基板上へのITO薄膜の製膜条件を最適化し、膜厚100 nmで<10^-3 Ohm cmの低抵抗ITO薄膜を形成できたので報告する。

DOI： 10.14886/sssj2008.36.0_132

CiNii Article

掲載種別：研究論文（学術雑誌）  

Ni(111)、(100)、(110)表面でのSi吸着後形成されるシリサイド構造を超高真空下でSTM観察を行った。Ni(111)表面では、Siが1/3ML吸着したroot-3構造が安定構造であり、Ni(100)表面では1/2MLのroot-2構造、Ni(110)表面では1/2MLのp(1x2)、c(2x2)、c(4x2)構造が共存することが分かった。

DOI： 10.14886/sssj2008.36.0_411

CiNii Article

掲載種別：研究論文（学術雑誌）   共著区分：単著  

DOI： 10.24544/ocu.20171218-067

CiNii Article

掲載種別：研究論文（学術雑誌）   共著区分：単著  

  Fundamental aspects for low- and medium-vacuum regions are described. Some long-standing problems, such as slip flow, pumpdown curve for viscous flow region, and vacuum drying are presented. The importance of slip velocity at a pipe wall for the Knudsen number between 0.01 and 0.1 is enlightened. A numerical result for a pumpdown curve with a pressure dependent conductance in the viscous flow regime was presented with an emphasis on a <i>t</i>⁻¹ pressure decrease. In addition, vacuum drying process is modeled with a water containing capillary and pressure dependent mass flow is discussed.<br>

DOI： 10.3131/jvsj2.58.325

CiNii Article

掲載種別：研究論文（学術雑誌）   共著区分：共著  

掲載種別：研究論文（学術雑誌）  

掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.susc.2012.03.024

掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.susc.2012.03.024

掲載種別：研究論文（学術雑誌）  

半導体上の金属吸着の研究例は非常に多いが、金属上の半導体や絶縁体形成初期に関する研究は多くはない。本研究では、ニッケル(111)表面に、典型的な半導体であるシリコンを吸着させたときの初期吸着挙動を超高真空STMを用いて調べた。室温吸着したシリコンは表面原子とは反応せず、孤立して、もしくはデンドリマー状に集合し、特定の超構造をとらないことが分かった。

DOI： 10.14886/sssj2008.30.0.188.0

CiNii Article

掲載種別：研究論文（学術雑誌）  

半導体上の金属吸着の研究例は非常に多いが、金属上の半導体や絶縁体形成初期に関する研究は多くはない。本研究では、ニッケル(111)表面に、典型的な半導体であるシリコンを吸着させたときの初期吸着挙動を超高真空STMを用いて調べた。室温吸着したシリコンは表面原子とは反応せず、孤立して、もしくはデンドリマー状に集合し、特定の超構造をとらないことが分かった。

DOI： 10.14886/sssj2008.30.0.188.0

CiNii Article

掲載種別：研究論文（学術雑誌）  

掲載種別：研究論文（学術雑誌）   共著区分：単著  

掲載種別：研究論文（学術雑誌）  

The atomic geometries and electronic band structures of Cu-embedded Ni(110) surfaces were studied theoretically. First principles calculation with spin-resolved local density functional theory was applied to the Ni(110) surface, and one to four Cu-embedded Ni(110) surfaces in the 2&times;2 surface unit cell. The optimized structures for the Ni(110) surface showed that interlayer spacing between the first and the second layer shrunk 11.1% of the bulk distance, but the second and third layer spacing expanded by 2.9% in agreement with previous studies. For the Cu-embedded surfaces, embedded Cu atoms are 11-14 pm higher than the top Ni atoms, which is about four times larger than the difference of the atomic radii. The detailed band structures and corresponding local density of states (LDOS) were calculated. At the embedded Cu atom sites, the surface LDOS near the Fermi level was reduced in agreement with previous scanning tunneling microscopy observation. In addition, by increasing the number of Cu atoms in the top layer, magnetic moments were decreased near the surface regions. [DOI: 10.1380/ejssnt.2009.681]

DOI： 10.1380/ejssnt.2009.681

CiNii Article

掲載種別：研究論文（学術雑誌）  

DOI： 10.1103/PhysRevB.78.195422

掲載種別：研究論文（学術雑誌）  

We studied initial Cu overlayer formation on the Ni(110) surface by scanning tunneling microscopy (STM) in an ultrahigh vacuum. Initially, deposited Cu displaces the top Ni layer, forming two-dimensional Cu-Ni alloy on the substrate. The Cu atom embedded into the top layer was depressed in the STM image. The depression due to the lack of Ni 3d-derived surface local density of states was confirmed by the first-principles calculation. Ni atoms squeezed out from the top substrate layer agglomerated in the anisotropic Ni island along the close-packed (1 (1) over bar0) direction. Further Cu deposition resulted in a Cu-Ni mixed island. Quantitative measurement of the Cu fraction on the substrate showed that 0.71 +/- 0.04 of deposited Cu was embedded in the top Ni layer, whereas significant Cu enrichment was seen on the island.

DOI： 10.1103/PhysRevB.78.195422

掲載種別：研究論文（学術雑誌）   共著区分：単著  

DOI： 10.3131/jvsj2.51.682

CiNii Article

掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.apsusc.2008.01.143

掲載種別：研究論文（学術雑誌）  

Copper overlayer formation on the Ni(1 1 0) surface was studied by scanning tunneling microscopy (STM) in an ultrahigh vacuum. Atom-resolved STM images showed that initially deposited Cu is replaced with surface Ni atoms forming atom-size depressions on the Ni(1 1 0) terraces and a Ni-rich quasi-one-dimensional island along the [1 (1) over bar 0] direction. Further Cu deposition yields a mosaic structure on the islands, indicating Cu/Ni mixed layer formation. From the quantitative measurement of the Cu/Ni ratio on the substrate and the islands, impinging Cu will be replaced with surface Ni whereas expelled Ni and directly impinging Cu to the island form the mixed island. The number of Cu atoms in the islands, however, more than the directly impinging Cu, indicate significant Cu/Ni replacement at the periphery of the island. (C) 2008 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.apsusc.2008.01.143

掲載種別：研究論文（学術雑誌）  

CiNii Article

掲載種別：研究論文（学術雑誌）  

掲載種別：研究論文（学術雑誌）  

掲載種別：研究論文（学術雑誌）  

DOI： 10.11316/jpsgaiyo.63.1.4.0_872_4

CiNii Article

掲載種別：研究論文（学術雑誌）  

DOI： 10.3131/jvsj2.51.682

CiNii Article

掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.susc.2006.03.035

掲載種別：研究論文（学術雑誌）  

Initial hydrogen adsorption on the Si(111) 7 x 7 surface was studied by scanning tunneling microscopy (STM) in an ultrahigh vacuum. Room temperature adsorbed hydrogen on the adatom in the 7 x 7 reconstruction led to depression of adatoms in the STM images. The hydrogen uptake curve at the adatom site as a function of hydrogen exposure time was well represented by Langmuir adsorption. No preferential adsorption was seen among four inequivalent adatoms in the 7 x 7 reconstruction. Adsorption of the adjacent center and corner adatoms respectively showed similar to 10% higher adsorption. Even though the number of reacted adatoms in the half unit of the 7 x 7 reconstruction was statistically random, the number of reacted adatoms in the nearest neighbor half unit was enhanced as the number of reacted sites increased in the half unit. (c) 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.susc.2006.03.035

掲載種別：研究論文（学術雑誌）  

We performed in situ scanning tunneling microscopy observation of oxygen reaction on the Si(111)7×7 surface at high temperatures. In spite of passive oxidation regime, we found that voids having the depth just one bilayer were formed at the initial stage of reaction. We found that the number density of the void was well represented by power laws. We applied the two-dimensional nucleation theory to this void formation and found that the critical nuclei were <i>i</i> = 1.46(647 K) and <i>i</i> = 14.7(751 K). We found the transition from active to passive oxidation with constant substrate temperature and oxygen exposure rate. The transition was quantitatively reproduced by the numerical simulations.

DOI： 10.3131/jvsj.48.350

CiNii Article

J-GLOBAL

We performed in situ scanning tunneling microscopy observation of oxygen reaction on the Si(111)7×7 surface at high temperatures. In spite of passive oxidation regime, we found that voids having the depth just one bilayer were formed at the initial stage of reaction. We found that the number density of the void was well represented by power laws. We applied the two-dimensional nucleation theory to this void formation and found that the critical nuclei were <i>i</i> = 1.46(647 K) and <i>i</i> = 14.7(751 K). We found the transition from active to passive oxidation with constant substrate temperature and oxygen exposure rate. The transition was quantitatively reproduced by the numerical simulations.

DOI： 10.3131/jvsj.48.350

CiNii Article

対象： 研究者,　学術団体

参加者数：450（人）

2020年日本表面真空学会学術講演会のプログラム委員長として学会運営、プログラム編成の指揮を執った。

対象： 社会人・一般,　学術団体

JIS規格Z8126-1の原案について調査、討議した。

対象： 研究者,　社会人・一般,　企業

参加者数：60（人）

対象： 社会人・一般

参加者数：130（人）

対象： 研究者,　社会人・一般,　企業

参加者数：60（人）

対象： 研究者,　社会人・一般,　企業

参加者数：56（人）