Numerical analysis of crystal growth of an InAs-GaAs binary semiconductor under microgravity conditions

• Material Type: 文書・図像類
• Title: Numerical analysis of crystal growth of an InAs-GaAs binary semiconductor under microgravity conditions
• Author/Editor: 平岡, 良章; 池上, 圭介; 前川, 透; 松本, 聡; Hiraoka, Yoshiaki; Ikegami, Keisuke; Maekawa, Toru; Matsumoto, Satoshi
• Author Heading: 平岡, 良章; 池上, 圭介; 前川, 透; 松本, 聡; Hiraoka, Yoshiaki; Ikegami, Keisuke; Maekawa, Toru; Matsumoto, Satoshi
• Publication, Distribution, etc.: 宇宙開発事業団
• Publication Date: 2000-09-29
• Publication Date (W3CDTF): 2000-09-29
• Alternative Title: 微小重力条件でのInAs-GaAsバイナリ半導体の結晶成長の数値解析
• Periodical title: NASDA Technical Memorandum
• Pages: 29-41
• ISSN (Periodical Title): ISSN : 1345-7888
• Text Language Code: eng
• Subject Heading: InAs-GaAs; バイナリ半導体; 微小重力; 結晶成長法; 2元結晶; 溶液結晶界面; 境界フィット法; 運動境界相転移問題; 国際宇宙ステーション; gジッタ; ソレー効果; 温度差; 濃度差; 重力加速; 単成分結晶; InAs GaAs; binary semiconductor; microgravity; crystal growth method; binary crystal; solution crystal interface; boundary fit method; moving boundary phase transition problem; International Space Station; g jitter; Soret effect; temperature difference; concentration difference; gravitational acceleration; single component crystal
• Target Audience: 一般
• Note (General): 宇宙での一様な2元化合物結晶の成長の可能性を数値的に研究し、新しい結晶成長法を提案した。溶液中での温度差、濃度差によって引き起こされる対流を考慮した2元結晶の成長の数値計算法を開発した。単成分結晶に比べ複雑な2元結晶について、結晶成長中の溶液結晶界面の形と運動を決定する方法を明快に示した。この運動境界相転移の問題を解くために境界フィット法を採用した。この計算方法をInAs-GaAs バイナリ半導体の結晶成長に応用し、微小重力下で引き起こされる浮力対流が結晶成長過程に及ぼす影響を調べた。高濃度場は国際宇宙ステーションで期待される、10(exp -6)g 程度の低い重力下でも浮力対流によって擾乱され、結果として溶液結晶界面が歪められることがわかった。残余重力の方向が、溶液中での高濃度場と結晶成長過程に強い影響を与えることもわかった。次にgジッタとソレー効果が結晶成長過程に与える影響についても解析した。実際、gジッタとソレー効果は巨視的結晶成長過程にはほとんど影響を与えないことがわかった。溶液中での過冷却生成の対流に対する依存性も調べた。残余重力が10(exp -6)gの場合、対流によって過冷却が引き起こされることはないことがわかった。最後に、宇宙での一様成分の高品質InGaAs結晶の成長の可能性について議論した。; The possibilities of growing a uniform binary compound crystal in space numerically are investigated proposing a new crystal growth method. A numerical calculation method of the growth of binary crystals is developed in which convection induced by temperature and concentration differences in the solution is taken into account. How to determine the shape and movement of the solution-crystal interface during the crystal growth is clearly explained for binary crystals, which is more complicated than that for single-component crystals. The boundary fit method is employed to solve this moving boundary phase transition problem. The calculation method is applied to the crystal growth analysis of an InAs-GaAs binary semiconductor and the effect of buoyancy convection induced under micrigravity conditions on the crystal growth process is investigated. It was found that the concentration field is disturbed and, as a result, the solution-crystal interface is deformed by buoyancy convection even when the gravitational acceleration is as low as 10(exp -6)g, which is supposed to be the gravity level in the International Space Station (ISS). It was also found that the direction of residual gravity has a strong effect on the concentration field in the solution and the crystal growth process. Next, the influence of g-jitters and the Soret effect on the crystal growth process are analyzed. It was, in fact, found that g-jitters and the Soret effect have little influence on the macroscopic crystal growth process. The dependence of the generation of supercooling in the solution on convection is also investigated. It was found that supercooling is not induced by convection if residual gravity is 10(exp -6)g. Finally, the possibility of growing high quality InGaAs crystals of uniform compositions in space is discussed.; 資料番号: AA0029300003; レポート番号: NASDA-TMR-000007E
• Access Restrictions: 限定公開
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