表面科学
Online ISSN : 1881-4743
Print ISSN : 0388-5321
ISSN-L : 0388-5321
26 巻 , 6 号
選択された号の論文の11件中1~11を表示しています
巻頭言
特集:半導体表面
  • 鷺坂 恵介, 藤田 大介
    原稿種別: 研究紹介
    2005 年 26 巻 6 号 p. 306-314
    発行日: 2005/06/10
    公開日: 2007/10/04
    ジャーナル フリー
    Scanning tunneling microscopy (STM) and spectroscopy (STS) were used to study the surface phase manipulation between c(4×2) and p(2×2) on the Si(100) surfaces at 6 K. We found that there is a correlation between the sample voltage range that induced p(2×2) (c(4×2)) and the energy position of the π* (π) state with respect to the Fermi level. This suggests that electron injection into the π* state caused the emergence of p(2×2), while the hole injection into π state retrieved the c(4×2) surfaces. Moreover, field emission from the STM tip and the subsequent STM observation confirmed that electron beam irradiation onto the Si(100) surfaces caused flip-flop motion of dimers. Such findings resolved recent controversy in the observations of the Si(100) surfaces at low temperatures using STM and low energy electron diffraction. We concluded that the c(4×2) structure is the most stable and the p(2×2) phase is a meta-stable structure.
  • 中辻 寛, 高木 康多, 吉本 芳英, 小森 文夫
    原稿種別: 研究紹介
    2005 年 26 巻 6 号 p. 315-321
    発行日: 2005/06/10
    公開日: 2007/10/04
    ジャーナル フリー
    The structure of the clean Ge(001) surface is locally and reversibly changed between c(4×2) and p(2×2) by controlling the bias voltage of a scanning tunneling microscope (STM) below 80 K. It shows hysteresis for the direction of the sample bias voltage change. The c(4×2) structure is observed with a sample bias voltage Vb ≤ −0.7 V. This structure is maintained at Vb ≤ 0.7 V with increasing the bias voltage. When Vb is higher than 0.8 V, the structure changed to p(2×2). This structure is then maintained at Vb ≥ −0.6 V with decreasing the bias voltage. The area of the structure change can be confined in the single dimer row under the STM tip using a bias voltage pulse. The observed local change of the reconstruction is attributed to the energy transfer process from the tunneling electron to the Ge lattice in the local electric field due to the STM bias voltage. A phenomenological model is proposed for the structure changes.
  • 田尻 寛男, 隅谷 和嗣, 高橋 敏男
    原稿種別: 研究紹介
    2005 年 26 巻 6 号 p. 322-328
    発行日: 2005/06/10
    公開日: 2007/10/04
    ジャーナル フリー
    The in-plane structures of the Si(111)-√3×√3-Ag surface at both room temperature (RT) and 50 K are determined by synchrotron X-ray diffraction. The honeycomb chained triangle model with strongly anisotropic thermal vibrations of Ag atoms is preferred over the inequivalent triangle (IET) model at RT. On the other hand, at 50 K, the IET model better explains the experimental results. Not only ordinary Bragg reflection peaks but also broad reflection peaks are observed below the phase transition temperature of Tc=150±4 K accompanied by the formation of the twin IET structure. The critical exponent β obtained from the broad peaks is 0.27±0.03, that is not explained by simple two-dimensional order-disorder transition models. The temperature dependence of the Bragg intensities also supports a displacive transition.
  • 中村 美道, 渡邉 聡
    原稿種別: 研究紹介
    2005 年 26 巻 6 号 p. 329-335
    発行日: 2005/06/10
    公開日: 2007/10/04
    ジャーナル フリー
    Recently, a major revision has been made in the interpretation of the STM images of Si(111)√3×√3-Ag surface from the viewpoint of the surface fluctuation. So far, little attention has been paid to the possibility of the surface fluctuation because the STM images of this surface reveal clear arrangement of bright spots. The studies introduced in this article provide not only a unified understanding of the observed STM images of Si(111)√3×√3-Ag surface, but also an important warning to our common tendency to relate STM images revealing clear arrangement of bright spots with a stable structure.
  • 市川 禎宏
    原稿種別: 研究紹介
    2005 年 26 巻 6 号 p. 336-343
    発行日: 2005/06/10
    公開日: 2007/10/04
    ジャーナル フリー
    Twenty eight years have passed since a pioneering LEED study of Ge(110) surface reconstruction was published by Olshanetsky et al. in 1977, and now natures of the reconstruction are rapidly being clarified. In the present article, experimental studies on the structures of the reconstructed surfaces so far performed are surveyed, and a 16×2 structure is concluded to be only a stable structure on reconstructed Ge(110) surfaces at temperatures below 430oC. Atomic geometries of the 16×2 and a metastable c(8×10) structures are studied through STM observations and first-principle structural optimization calculations, and new models of the two structures are presented, in which five-membered clusters of Ge adatoms are shown to be fundamental structural elements of their structures.
  • 長尾 忠昭, 柳沼 晋, J.T. SADOWSKI, 斉藤 峯雄, 藤川 安仁, 大野 隆央, 長谷川 修司, 櫻井 利夫
    原稿種別: 研究紹介
    2005 年 26 巻 6 号 p. 344-350
    発行日: 2005/06/10
    公開日: 2007/10/04
    ジャーナル フリー
    Group V elements are known to show rich allotropic transformation because their semimetallic bonding character can be easily shifted to either metallic or covalent side, for example by changing the applied pressure. Here, we report on our finding that such an allotropic transformation can be induced also by the change in the thickness of the film of Bi on the scale of several atomic layers. Our scanning tunneling microscopy and electron diffraction experiments revealed that a new two-dimensional allotrope of Bi forms on the Si surface. This pseudocubic {012}-oriented allotrope is stable up to several atomic layers at room temperature. As the thickness increases, the entire volume of the film transforms into a bulk single-crystal (001) phase, due to the increase in the bulk contribution to the cohesion. Based on our ab initio calculations, we propose that the new allotrope consists of black-phosphorus-like puckered-layers stabilized by saturating all the pz dangling bonds in the film. The resulting film is very flat, compared to the growth of any known metal films, reflecting the inherent two-dimensional (2D) structure of the {012} and the (001) phases.
  • 森田 清三, 杉本 宜昭, 大藪 範昭, Óscar CUSTANCE, 西 竜治, 清野 宜秀, 李 仁淑, 阿部 真之
    原稿種別: 研究紹介
    2005 年 26 巻 6 号 p. 351-356
    発行日: 2005/06/10
    公開日: 2007/10/04
    ジャーナル フリー
    In this review article, at first, we introduced recent developments of powerful and sensitive atomic force microscope (AFM). Then, we introduced recent three topics related to AFM. The first one is an atom selective imaging of semiconductor surfaces with intermixed Si and Sn adatoms at room temperature (RT), i.e., chemical discrimination of two atom species on semiconductor surfaces at RT. The second one is vertical and lateral atom manipulations of semiconductor atoms based on the mechanical method at low temperature (LT). The last one is a novel atom manipulation method that enables us to create complex nanostructures assembled from more than two atom species at RT. Using this novel atom manipulation method, we constructed “Atom Inlay” at RT, i.e., atom letters “Sn” consisting of Sn atoms embedded in Ge atoms.
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