| Project/Area Number |
09450004
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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 |
Applied materials science/Crystal engineering
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| Research Institution | Tohoku University |
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Principal Investigator |
SUEZAWA Masashj Institute for Materials Research, Tohoku University Professor, 金属材料研究所, 教授 (00005919)
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| Project Period (FY) |
1997 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥5,000,000 (Direct Cost: ¥5,000,000)
Fiscal Year 1998: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1997: ¥4,000,000 (Direct Cost: ¥4,000,000)
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| Keywords | Si / interstitial atom / hydrogen / complex / formation energy / quenching / electron-irradiation / 電子照射 / 格子間原子 |
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| Research Abstract |
The aim of this project was to clarify the properties of interstitial Si atoms existed at high temperature in Si crystals. We measured optical absorption spectra of three kinds of crystals.
The first crystals were grown in H_2 gas. Many sharp peaks such as 2223 cm^<-1> peak were observed only when the crystal was doped with C or B, both of which have smaller covalent radii than that of Si. This result supports a hypothesis that those optical absorption peaks are due to complexes of H and interstitial Si atoms since crystals doped with such impurities have been known to include high density of interstitial Si atoms.
The second crystals were Au-doped Si annealed and quenched in H^2 gas. We succeeded to observe the 2223 cm^<-1> peak in this crystal. This also supports the above hypothesis that interstitial Si atoms included in the complex responsible for this peak since the concentration of interstitial Si atoms is known to be high in Au-doped Si. The formation energy of interstitial Si atom in Au-doped Si was determined to be about 2.1 eV.
The third crystal was electron-irradiated Si doped with H.We observed the 2223 cm^<-1> peak in these crystals. This is the first evidence to directly show the existence of interstitial Si in electron-irradiated Si.
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