@techreport{oai:jaxa.repo.nii.ac.jp:00041097,
 author = {龍見, 雅美 and 村井, 重夫 and 白川, 二 and 荒木, 高志 and 藤原, 伸介 and Tatsumi, Masami and Murai, Shigeo and Shirakawa, Tsuguru and Araki, Takashi and Fujiwara, Shinsuke},
 month = {Oct},
 note = {3元系化合物半導体であるIn(1-x)Ga(x)As;x=0.03結晶を、地上で水平ブリッジマン法(HB法)と垂直ブリッジマン法(VB法)を用いて成長させた。さらに微小重力環境下においてブリッジマン法で成長させることによって、融液対流と偏析現象に関する研究を行った。そして微小重力環境下で結晶成長を行うことによる、均一な組成を持った3元系結晶育成の可能性を調査した。地上でHB法で成長したInGaAs結晶中のGaの偏析係数は3.2であり、微小重力環境下で成長した結晶中のGaの偏析係数は2.6であった。種結晶部では直径が細い(4mm)ため、偏析係数が1になること、すなわちGa組成が均一になることが期待されていたが、Ga組成の均一化は得られなかった。これらの結果はCamelの予測と一致し、InGaAsの系では、微小重力環境下での結晶成長においてさえ、Ga組成の均一化が困難であるという結論を得た。しかしながら、InGaAs結晶をVB法で成長させれば、均一なGa組成分布を持つ結晶を育成できることを見いだした。この結晶の成長初期部には、Ga濃度の遷移領域が観察された。VB法でのGa組成の均一化は、Camelの理論では説明できない。初期の遷移領域のGa濃度分布は、Tillerの理論に良く一致し、この理論からGaの平衡偏析係数として3.1を得た。この値は、他の結晶成長実験から算出した値と、良い一致を示す。しかしながら、この理論から算出したInGaAs融液中のGaの拡散係数は4.1x10{-5}/s平方センチメートルであり、他の実験から求めた値の約3倍であった。, Crystal growth of In(1-x)Ga(x)As (x = 0.03) ternary compound semiconductor was carried out by using Horizontal Bridgeman (HB) method and Vertical Bridgeman (VB) method on ground surface. Moreover, on the case of crystal growth by means of Bridgeman method under microgravity, the study on convection of melts and segregation phenomena were performed, and based on this study, the possibility obtaining the ternary crystal with homogeneous composition by conducting crystal growth under microgravity was investigated. The segregation coefficient of Ga in InGaAs crystal made by HB method on ground surface was 3.2 and the segregation coefficient of Ga in InGaAs made under microgravity was 2.6. In part of the seed crystal, because of thin diameter (4 mm), although it was expected that segregation coefficient would become 1, that is, composition of Ga would become homogeneous, homogenization of Ga composition was not reached. Accordance of these results with the predictions by Camel theory led to the conclusion of that in InGaAs system, it was difficult to homogenize Ga composition even in crystal growth under microgravity. However, when InGaAs crystal in grown by means of VB method, it is found out to be possible to obtain a crystal with homogeneous distribution of Ga composition. The transitional region of Ga concentration was observed in the initial part of this crystal. The phenomenon of homogenization of Ga composition in case of VB method can not be explained by Camel theory. The distribution of Ga concentration in initial transitional part fairly agreed with Tiller theory, and the equilibrium segregation coefficient of Ga was derived to be 3.1 from this theory. This value is fairly coincident with the values calculated from the results of other experiments on crystal growth. However, the diffusion coefficient of Ga in InGaAs melts calculated based on this theory is 4.1x10(exp -5) /sq cm /s. This value is three times of the value calculated from other experiments., 資料番号: AA0004116023, レポート番号: NASDA-TMR-940002 V.2},
 title = {無重力環境下における化合物半導体結晶の作製(InGaAsの研究)},
 year = {1994}
}