| Project/Area Number |
11555061
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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 | 展開研究 |
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| Research Field |
Thermal engineering
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| Research Institution | Toyo University |
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Principal Investigator |
MAEKAWA Toru Toyo Univ., Faculty of Engineering, Professor, 工学部, 教授 (40165634)
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| Co-Investigator(Kenkyū-buntansha) |
木下 恭一 NTT物性科学基礎研究所, 量子物性研究部, 主幹研究員
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| Project Period (FY) |
1999 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥12,300,000 (Direct Cost: ¥12,300,000)
Fiscal Year 2001: ¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 2000: ¥5,900,000 (Direct Cost: ¥5,900,000)
Fiscal Year 1999: ¥4,700,000 (Direct Cost: ¥4,700,000)
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| Keywords | Crystal growth / Microgravitv / Compound semiconductors / Uniform compound / Single crystals / 二元系化合物半導体 / 数値計算 / ゾーン法 / 均一組成 / 二元系 / 傾斜濃度 / 地上実験 / 宇宙実験 |
|---|
| Research Abstract |
I investigated the validity of a new growth method for producing binary semiconductor crystals, which have uniform compositions, utilizing microgravity conditions. First, I developed a calculation method of growth of binary semiconductor crystals from a macroscopic point of view based on thermofluid dynamics. The shape and movement of the solution-crystal interfaces as well as the flow, temperature and concentration fields can be estimated efficiently. The growth process of an InAs-GaAs binary crystal by the Bridgman and zone methods were investigated and the following results were obtained :
(a) Bridgman method :
(1) The temperature field is not seriously deformed by convection since the Prandtl number of the molten compound semiconductors is very small.
(2) The concentration field and the solution-crystal interface are deformed by buoyancy convection even under microgravity when the crystal growth direction is perpendicular to the residual gravity, since the Schmidt number is large.
(3) As the crystal size and the heat flux increase, the deformation of the concentration field and the solution-crystal interface becomes more extensive.
(b) Zonemethod :
(1) The convective velocity is reduced by employing the zone method.
(2) The velocity and the deformation of the temperature and concentration fields and the solution-crystal interfaces are reduced remarkably and, as a result, supercooling is suppressed by reducing the zone width.
(3) A uniform In0.3Ga0.7As single crystal may be grown by reducing the zone width to 15 mm and setting the temperature gradient in the zone at 10 K/cm.
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