| Budget Amount *help |
¥9,500,000 (Direct Cost: ¥9,500,000)
Fiscal Year 2005: ¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 2004: ¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 2003: ¥5,000,000 (Direct Cost: ¥5,000,000)
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| Research Abstract |
For irradiation of low-electron temperature plasma and radicals on the substrate surface, we separate electron-temperature controllable region from deposition region by orifice in inductively-coupled radio-frequency hydrogen-methane plasma. In case of 6-mm-diamter orifice, we find that nanocrystalline diamond is deposited on the substrate. Further, when the dilution ratio of methane in hydrogen is reduced to be less than 1 %, rather qualified nanocrystalline diamond is created. On the contrary, when the orifice diameter is enlarged, diamond-like carbon film is deposited. It is interpreted by a decrease in the hydrocarbon radical ratio of sp3/sp2 in the plasma. In order to apply this property on wide area film deposition, we employ a hollow-typed magnetron plasma source. A high density plasma can be produced by the effect of static magnetic and electric fields. By reducing the electron-temperature in the plasma source region, the sp2 radical density can de decreased. We find that nanoparticles with polyhedron surfaces composed by regular tetrahedron are grown in the low-electron temperature plasma. On the other hand, in high electron-temperature plasma, nanowalls made of graphite films are deposited. Such difference can be explained by the local change of sp2/sp3 components in the background film. In the low-electron temperature plasma, the ratio of sp3/sp2 becomes large, which results in the formation of nanoparticles with sp3 structure like a diamond. Damage to nucleation and growth due to energetic ions impinging on the substrate can be also reduced in the low-electron temperature plasma, where migration of reactants on the surface is promoted to produce nanoparticles with polyhedron structures.
In this way, the control of radicals in low-electron temperature plasma is quite effective for nucleation and growth of nanostructures.
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