| Project/Area Number |
10305023
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Electronic materials/Electric materials
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| Research Institution | TOHOKU UNIVERSITY |
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Principal Investigator |
MASAOKA Fujio Research Institute of Electrical Communication, Tohoku University, Professor, 電気通信研究所, 教授 (50270822)
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| Co-Investigator(Kenkyū-buntansha) |
SAKURABA Hiroshi Research Institute of Electrical Communication, Tohoku University, Research Associate, 電気通信研究所, 助手 (60241527)
ENDOH Tetsuo Research Institute of Electrical Communication, Tohoku University, Assistant Professor, 電気通信研究所, 助教授 (00271990)
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| Project Period (FY) |
1998 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥39,600,000 (Direct Cost: ¥39,600,000)
Fiscal Year 1999: ¥7,100,000 (Direct Cost: ¥7,100,000)
Fiscal Year 1998: ¥32,500,000 (Direct Cost: ¥32,500,000)
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| Keywords | Silicon dioxide / Flash memory / Structural analysis |
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| Research Abstract |
(1) Set-up of measurement instruments and data analyzing systems
By setting-up the measurement control software for the evaluation of SiOィイD22ィエD2 films, the set-up of the research facilities has been finished.
(2) Clarification of the injection charge dependent deterioration of electrical insulation characteristics
By varying the amount of injected charge into SiOィイD22ィエD2 films, the change of electrical characteristics during breakdown were measured. More specifically, the deterioration of the electrical insulation characteristics of SiOィイD22ィエD2 films were measured under different stress conditions and for different SiOィイD22ィエD2 film areas.
(3) Structural investigations of SiOィイD22ィエD2 films
The thickness uniformity of SiOィイD22ィエD2 films in dependence of the process conditions was analyzed by XPS (X-Ray Photoelectron Spectroscopy) and AFM (Atomic Force Microscope). As a result, SiOィイD22ィエD2 film uniformity can be improved if N-atoms are introduced during an early stage of film interface formation.
(4) Clarification of the injection charge dependent deterioration of electrical insulation characteristics
By analyzing the change of electrical characteristics of an 6.8 nm thick SiOィイD22ィエD2 film, before and after FN stressing, it is made clear that stressing generates neutral trap sites at a distance of 4.47 nm from the Si-cathode interface having a trap site energy of 2.3 eV. These trap sites are responsible for the deterioration of the electrical isolation characteristics. Moreover, the film thickness dependence on stress conditions was analyzed.
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