| Project/Area Number |
11694059
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| Research Category |
Grant-in-Aid for Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
固体物性Ⅰ(光物性・半導体・誘電体)
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| Research Institution | UNIVERSITY OF TOKYO |
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Principal Investigator |
HASEGAWA Shuji UNIV.TOKYO, DPT.PHYSICS, ASSOCIATE PROFESSOR, 大学院・理学系研究科, 助教授 (00228446)
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| Co-Investigator(Kenkyū-buntansha) |
SHIRAKI Ichiro UNIV.TOKYO, DPT.PHYSICS, POST-DOC.RESEARCHER, 大学院・理学系研究科, 学振特別研究員
NAGAO Tadaaki UNIV.TOKYO, DPT.PHYSICS, RESEARCH ASSOCIATE, 大学院・理学系研究科, 助手 (40267456)
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| Project Period (FY) |
1999 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥5,000,000 (Direct Cost: ¥5,000,000)
Fiscal Year 2000: ¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 1999: ¥2,500,000 (Direct Cost: ¥2,500,000)
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| Keywords | Surface electronic transport / Four-point probe / Surface-state band / Surface superstructure / Silicon / Scanning electron microscopy / Microfabrication / Surface atomic step |
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| Research Abstract |
(1) We have constructed an ultrahigh-vacuum scanning electron microscope-molecular beam epitaxy apparatus, in which a micro-four point probe (with 8μm-probe spacing) system, which has been developed in Denmark Technical University, has been installed. With this system, we measured electrical conductance of aimed surface areas with aid of the microscope.
(2) We have found that the electrical conductance of a Si(111)-√3×√3-Ag surface is higher than that of a Si(111)-7×7 clean surface by two orders of magnitude. This is because the measurements become surface-sensitive due to the small probe spacing so that the intrinsic properties of the respective surfaces are directly detected.
(3) By shifting the micro-four point probe along the sample surface, we have found that the surface conductance is quite different between on terraces and across step bands. This directly means that the surface carriers are scattered by surface atomic steps, causing the reduction in conductance.
(4) We have done computer simulations using two-dimensional resistors networks to obtain the surface conductance maps of a sample from the measured conductance maps.
(5) A nano-four point probe (0.5μm probe spacing), which has been newly devised in Denmark Technical University, has been installed in the above-mentioned microscope, and used for surface conductivity measurements.
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