1989 Fiscal Year Final Research Report Summary
High growth rate deposition of diamond particles and thin films in arc and/or glow discharge region.
| Project/Area Number |
62550016
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Applied materials
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| Research Institution | Aoyama Gakuin University |
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Principal Investigator |
INUZUKA Tadao Aoyama Gakuin Univ., Dep. Elect. Eng. & Electronics, Prof., 理工学部, 教授 (30082788)
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| Co-Investigator(Kenkyū-buntansha) |
SAWABE Atsuhito Toshiba Co., R & D Center., 総合研究所・金属セラミック研究所 (70187300)
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| Project Period (FY) |
1987 – 1989
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| Keywords | Diamond / Chemical Vapor Deposition / Plasma / Thin Film / High Rate Growth / Epitaxial Growth |
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| Research Abstract |
Diamond thin films and particles have been grown by micro-wave or DC discharge plasma chemical vapor deposition(CVD) and the epitaxial growth of diamond has also been performed on cubic born-nitride surfaces.
By using micro-wave CVD, diamond thin films can be grown reproducibly with the growth rate of about 3000A/h and it is found that the quality of the films obtained is excellent except the lattice defects included in the films and particles.
For high rate deposition of diamond, it is revealed that DC discharge plasma CVD is quite useful. The growth rate of the films is about 20mum/h for the high quality one. On the other hand, if this method is operated under high methane concentration(2 3%)and high electric power density, the growth rate increases to about 100-200mum/h.
The characteristics of the plasma during diamond growth by DC discharge plasma CVD are measured by the Langmuir single probe method and emission spectrometry. For the source gas system of methane and hydrogen(gas ratio
… More
: CH_4/H_2=2/100, total gas pressure:2.6 10^4 Pa), it is found that the statistical temperatures of hydrogen atoms and electrons in the positive column of the plasma are obtained to be 4.8-5x10^3K and 1-1.1x10^5K respectively, and the amount of ionized species is fairly small(-10^<-7>).
By calculating the equilibrium constant of gas molecules in these temperature regions, it is found that the molecules over 99% (H_2 and CH_4) are decomposed to the neutral H and C atoms.
From these results, the preparation of atomic carbon and hydrogen plays important role for the growth of diamond at a low pressure.
In many experiments of diamond growth, the films grow in polycrystalline state. The epitaxial growth can not be performed yet. The reason of this fact is due to the stability of the substrate surfaces in hydrogen plasma.
Then, the cubic boron-nitride surfaces are used as a substrate. It is found that the diamond thin films can be grown epitaxially with the parallel orientation to the substrate surfaces. The single crystal films of diamond with (100) and (111) planes can be obtained with the detailed control of substrate temperature and supersaturation of active species.
There remained some problems for the growth of diamond particles useful for industrial fields. Less
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