1997 Fiscal Year Final Research Report Summary
Structural Study of Thin Amorphous SiO_2 and Si_3N_4 Films by the Grazing Incidence X-ray Scattering (GIXS) Method
| Project/Area Number |
08455290
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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 |
Physical properties of metals
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
MATSUBARA Eiichiro Kyoto University, Department of Materials Science & Engineering, Associate Professor, 工学研究科, 助教授 (90173864)
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| Project Period (FY) |
1996 – 1997
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| Keywords | amorphous film / grazing incidence x-ray scattering / silicon nitride / silicon oxide / atomic structure / x-ray diffraction / thin film / structural analysis |
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| Research Abstract |
A method for determining a local atomic structure in an amorphous thin film of sub-micron thick grown on a substrate by the grazing incidence x-ray scattering (GIXS) method is presented. This method has been demonstrated in amorphous SiO_2 and Si_3N_4 films of 200 and 70nm thick, respectively. A network structure in the amorphous SiO_2 film consists of SiO_4 tetrahedra connecting each other by oxygen atoms at their vertices. This resembles that in a bulk amorphous SiO_2 plate. The local ordering unit structure in the amorphous Si_3N_4 film is a SiN_4 tetrahedron. A significant feature in the present amorphous Si_3N_4 film is the presence of two types of Si-Si pairs in the near neighbor region while only one type is present in the alpha-Si_3N_4 crystal. This indicates that a part of the network structure formed by the SiN_4 tetrahedra is quite different from that in the crystal. According to the coordination number of 3.7 for Si-N pairs, there are some nitrogen vacancies in the film. The nitrogen vacancies may be responsible for the modified network structure in the present amorphous Si_3N_4 film.
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