| Project/Area Number |
06452335
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Material processing/treatments
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| Research Institution | Waseda University |
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Principal Investigator |
OSAKA Toshiaki Waseda University School of Science and Engineering Professor, 理工学部, 教授 (50112991)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥7,400,000 (Direct Cost: ¥7,400,000)
Fiscal Year 1995: ¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1994: ¥5,300,000 (Direct Cost: ¥5,300,000)
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| Keywords | Scanning tunneling microscope / InSb (111) A- (2x2) surface / Surface fine structure / Initial adsorption / InSb(111)A-(2×2)表面 / STM / In-vacancy buckling model |
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| Research Abstract |
Understanding of the formation process and atomic structure of interfaces in the metal/semiconductor system is very important for improvements in its technology. Therefore, although such interfaces have been studied extensively for decades, little work associated with the metal/compound-semiconductor system has been carried out.
In this work we report on the scanning tunneling microscopy (STM) study of the very initial stage of the interface formation in the Sn/InSb (111) A-2x2 system. So far this system has been the subject of RHEED investigation and DV-X alpha calculation. However, the question on "where is the Sn adsorbed on the InSb (111) A-2x2 surface? " has not been answered by direct methods such as STM.
The clean and well-defined substrate surface of InSb (111) A-2x2 could be reproducibly prepared in UHV by annealing a sample in the narrow range near 460ﾟC.STM observations of the InSb (111) A-2x2 surface reveal the In-vacancy buckling structure which has been already reported by Bohr et al. For example, the STM for the occupied states manifests itself in the images corresponding to the lone-pair of Sb in the second layr near the In-vacancy at a high bias and to the bonding orbitals between the outermost layr of In and the second layr of Sb at a low bias. Occasionally, bilayr steps, the edges of which are perpendicular to eht [112] or [112] direction were observed. A novel model of these step structures is proposed on the basis of the electron counting model. The Sn is non-periodically adsorbed on the following three sites of the InSb (111) A-2x2 surface ; on-top sites of the In-vacancy, of the Sb in the second layr, and of the In in the outermost layr. Of these adsorption sites, the on-top of In-vacancy is most favorably occupied by Sn.
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