2002 Fiscal Year Final Research Report Summary
Atomistic tunnelig barrier of heteroepitaxial SiO_2/Si(001)
| Project/Area Number |
13640322
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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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 | The University of Electro-Communications |
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Principal Investigator |
NATORI Akiko The University of Electro-Communications, Faculty of Electro-Communications, Professor, 電気通信学部, 教授 (50143368)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAMURA Jun The University of Electro-Communications, Faculty of Electro-Communications, Research Associate, 電気通信学部, 助手 (50277836)
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| Project Period (FY) |
2001 – 2002
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| Keywords | valence band offset / SiO_2 / Si / tunneling barrier / hole penetration depth / silicon dioxide |
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| Research Abstract |
Energy dispersion relation and probability distribution of the Bloch function at the band edge were calculated for SiO2/Si(100) super-lattice structure, using the density functional first-principles calculation. From the band edge energy and the probability distribution of the Bloch function, novel evaluation method of valence band offsets are proposed. This method can be available even if the layer thickness of the super-lattice is very thin, although the conventional method is appropriate for thick layers.
The following results have been obtained.
(1) SiO2 layer thickness dependence of valence band offsets and corresponding penetration depth of a hole : The valence band offsets decreases as SiO2 layer thickness decreases, due to decrease of the energy gap of SiO2. The penetration depth of a hole gives a consistent result with the valence band offset
(2) Si layer thickness dependence of valence band offsets and energy gap : The valence band offset decreases and the energy gap increases, as Si layer thickness decreases. This is due to quantum confinement effect in Si layer.
(3) Carrier injection dependence of valence band offsets : The valence band offsets increases as electron concentration increases, although the valence band offset decreases as hole concentration increases. This is attributed to change of the electrostatic potential by carrier injection.
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