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本文介绍利用一种将单晶锭条两端固定,中间可以重熔以建立悬浮熔区的反应容器,在回地卫星的微重力环境下用45分钟从熔区两端相向生长出中部直径为1cm,长度分别为10mm和7mm的两块火炬头状砷化镓单晶.对地面生长和空间生长7mm长单晶用KOH溶液为电解液的阳极腐蚀法显示,结果表明:在地面生长的籽晶部位观察到了由重力驱动对流引起温度涨落而造成的密排杂质条纹,在与籽晶相邻接的空间生长单晶部位未观察到这种类型的杂质条纹.同时观察到太空生长单晶边缘附近存在杂质条纹以及在太空单晶末端附近边缘出现胞状结构,它们可能是因降温速率快过冷所致.经熔融KOH腐蚀显示,在地面单晶和10mm长空间单晶交界面出现密排位错,靠近交界面的太空生长单晶位错密度较低,随着晶体生长位错密度逐渐增高,太空生长单晶边缘附近位错密度高于中心区域.
This article describes the use of a single crystal ingot fixed at both ends can be remelted in the middle to establish a suspended molten zone reaction vessel in the micro-gravity environment back to satellites 45 minutes from opposite sides of the melt growth of the middle diameter 1cm and length of 10mm and 7mm torch head gallium arsenide single crystal respectively.On the surface of the growth and space growth 7mm long single crystal KOH solution as the electrolyte of the anodic corrosion method showed the results: Crystal structure was observed by the gravity-driven convection caused by temperature fluctuations caused by the dense stripes of impurities in the seed crystal adjacent to the growth of single-crystal site is not observed in this type of impurity stripes observed at the same time space-grown single crystal The presence of impurity fringes near the edges and the presence of cell-like structures near the ends of the space single crystal may be due to the rapid cooling rate due to the cooling rate.According to the KOH corrosion of the melt, close-packed Dislocation, the dislocation density of space grown single crystal near the interface is relatively low, and the density of dislocations near the edge of space grown single crystal is higher than that of the central region as the crystal growth dislocation density increases.