| Project/Area Number |
15340101
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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 |
Condensed matter physics I
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| Research Institution | Osaka University (2004)
Osaka City University (2003) |
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Principal Investigator |
KANASAKI Jun'ichi Osaka University, The Institute of Scientific and Industrial Research, Associate Professor, 産業科学研究所, 助教授 (80204535)
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| Co-Investigator(Kenkyū-buntansha) |
TANIMURA Katsumi Osaka University, The Institute of Scientific and Industrial Research, Professor, 産業科学研究所, 教授 (00135328)
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| Project Period (FY) |
2003 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥12,700,000 (Direct Cost: ¥12,700,000)
Fiscal Year 2004: ¥3,900,000 (Direct Cost: ¥3,900,000)
Fiscal Year 2003: ¥8,800,000 (Direct Cost: ¥8,800,000)
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| Keywords | semiconductor / surface / electronic excitation / laser beam / new phase formation / scanning tunneling microscope / silicon / tunneling spectroscopy / 新構造層 / 半導体表面 / 光誘起結合切断 / 電子励起効果 / レーザー光 / 空格子点 |
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| Research Abstract |
1.We studied laser-induced bond breaking and new phase formation on Si(001)-(2x1) surfaces, and obtained the results as follows :
(1)Repeated irradiation induces progressive growth of vacancies as well as newly formation of monovacancies. Vacancy clusters elongated along dimer rows are predominantly formed on the surface, indicating a strong site-dependent rate of bond breaking
(2)Excitation above 100mJ/cm2 induces formation of ad-dimers on the terrace, and then ad-dimer islands are produced under repeated excitation Laser-induced ad-dimer formation disturbs the formation of defect-free atomic-leveled flat surface.
(3)Scanning tunneling microscopic(STM) study revealed that laser-induced removal of surface dimers forms a new phase, which has never been obtained by thermal processes. We succeeded in removing 95 % of surface dimers by repeated irradiation.
2.We studied structural instability of the Si(111)-(7x7) surface induced by low energy electron excitation, and obtained the following result.
(1)Low energy electron induces removal of adatoms from the Si(111)-(7x7) surface, rate of which is linear with respect to excitation flux and is strongly dependent on the primary energy of electron beam. We proposed plasmon-related bond breaking mechanism for explaining the electron-induced structural instability.
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