2006 Fiscal Year Final Research Report Summary
Research on atomic structure analysis of silicon carbide semiconductor single crystal and interface of oxide film
| Project/Area Number |
17560298
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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 |
Electronic materials/Electric materials
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| Research Institution | Japan Atomic Energy Agency |
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Principal Investigator |
MIYASHITA Atsumi Japan Atomic Energy Agency, Quantum Beam Science Directorate, Assistant Principal Researcher, 量子ビーム応用研究部門, 研究副主幹 (00354944)
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| Co-Investigator(Kenkyū-buntansha) |
YOSHIKAWA Masahito Japan Atomic Energy Agency, Quantum Beam Science Directorate, Principal Researcher, 量子ビーム応用研究部門, 研究主幹 (40354948)
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| Project Period (FY) |
2005 – 2006
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| Keywords | Silicon Carbide / First-Principles Calculation / Molecular Dynamics / Interfacial Structure / Defect Level |
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| Research Abstract |
Silicon carbide (SiC) devices don't present the theoretically expected performance. This is considered to be attributed to the SiO_2/SiC interface defects that degrade the electrical performance of them. In this study, we tried to solve these problems by the computer simulation. For the application of computer simulation to the realistic interface structures, it is important to construct the structure of amorphous SiO_2 (a-SiO_2) on SiC. The slab model using 693 atoms for a-SiO_2 on a 4H-SiC (0001) crystal layer was constructed by using first-principles molecular dynamics (MD) method. The calculations have been performed by the VASP code on the Earth-Simulator. The heating and quenching method was carried out to make an a-SiO_2/SiC interface structure. The SiO_2 layers melted heating the interfacial structure by 2 ps in the temperature of 4000K on the condition of fixing SiC layers except 2 interfacial layers, surface Si of SiO_2 layers and H that terminate surface Si. The interfacial
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structure has been cooled down to the temperature of 3500K without changing the restriction. After the removal of H and release of surface Si, the interfacial structure was continuously annealed for 2 ps at the temperature of 3500K. After free interfacial SiC layers had been expanded from two layers to four layers, the interfacial structure was quenched to the room temperature. The radial distribution function (RDF) of the SiO_2 layers was calculated. The nearest neighbor interatomic distance between Si and O became 0.165 nm. The nearest neighbor interatomic distance between Si and Si became 0.305 nm. When this distance is converted into Si-O-Si bond angle, it becomes 135 deg. This angle agrees well with Si-O-Si bond angle in the silica glass. The nearest neighbor interatomic distance between 0 and 0 became 0.268 nm, and is converted into O-Si-O bond angle of 109 deg. This angle is almost equal to bond angle of 109.5 deg in Si-atom-centered tetrahedra. It was confirmed to be able to generate the a-SiO_2 layer with the simulation of the heating and quenching method. Less
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Research Products
(9 results)
