蓝宝石长晶过程中Ga元素的性能研究
Study on the Properties of Ga Element in the Process of Sapphire Crystal Growth

本文通过两组长晶实验，对比研究了大尺寸蓝宝石晶体生长过程中Ga元素对晶体生长的影响及元素可能的存在形式。实验采用泡生法进行长晶，使用辉光放电质谱仪进行杂质元素检测。具体是通过投入Ga元素含量为<0.1 ppm和14 ppm的超高纯氧化铝原料，对比分析所产出晶体、底料、炉灰中Ga元素的含量。研究得到，两组实验产出晶体品质良好，晶体和底料中几乎不含Ga元素。但是原料和炉灰中的Ga含量呈现一定的相关性，原料中Ga含量越高，挥发到炉灰中的Ga含量越高。分析认为，原料中的Ga元素与溶液中的O、S、P等元素结合形成熔点较低的化合物，如Ga2O、Ga2O3、GaS、Ga2S3、GaP。这些化合物在晶体生长过程中，随着功率的降低，会落到上保温屏、顶腔、炉腔壁等温度较低的位置，最终以固体形式富集到炉灰中。
In this paper, the influence of Ga element on the growth of large-sized sapphire crystal and the possible forms of elements are studied by two group crystal experiments. The crystal was grown by KY method and the contents of impurity elements were detected by GDMS method. Specifically, ultra-high purity Al2O3 materials with Ga content of <0.1 ppm and 14 ppm are inputting. It is con-trastively analyzed the content of Ga in the crystal, bottom material and ash. The results show that the crystal quality of the two groups is well, and there is almost no Ga element in the crystal and the substrate. However, there is a certain correlation between the Ga content in the raw material and the ash. The higher Ga content in the raw material, the higher Ga content volatilized to the ash. The analysis shows that Ga element in raw material combines with O, S, P and other elements in solution to form compounds with lower melting point, such as Ga2O, Ga2O3, GaS, Ga2S3, and GaP. In the process of crystal growth, with the decrease of power, these compounds will fall to the lower temperature positions such as the upper insulation screen, top chamber and furnace wall, and finally accumulate in the ash in the form of solid.