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多晶硅是主要功能半导体材料。磷作为主要施主杂质,其含量直接影响多晶硅的半导体性能。多晶硅制备普遍采用改良西门子工艺,在密闭、复杂的动态工艺系统中,磷存在的化合物、含量及转化,无法实际有效掌握、但又非常重要;利用Aspen plus等软件对流程中主要的工艺系统模拟计算,并结合热力学反应分析,研究磷的分布规律、存在形式和量化含量;研究发现磷的主要化合物类型除PCl3,在还原或氢化炉这种高温、富氢条件下,PCl3会转化成PH3。在还原过程中磷存在富集效应。尾气回收解析塔解析效果的好坏影响着磷去除效果。研究结果表明,若要使还原多晶硅产品符合国标太阳能三级磷≤7.74ppba的要求,则对本文建立的模拟工艺流程,需要精馏前、后的SiHCl3中P应分别≤2557 ppbw和1.79ppbw。
Polysilicon is the main functional semiconductor material. Phosphorus as the main donor impurity, its content directly affects the semiconductor properties of polysilicon. In the process of closed and complicated dynamic process, the compound, content and conversion of phosphorus can not be effectively controlled, but it is very important. The software of Aspen plus is used to simulate the main process system in the process Calculated, and combined with the analysis of thermodynamic reactions to study phosphorus distribution, existing forms and quantitative content; study found that the main type of phosphorus compounds except PCl3, reduction or hydrogenation furnace in this high temperature, hydrogen-rich conditions, PCl3 will be converted to PH3. Phosphorus is enriched in the reduction process. Exhaust gas recovery tower analytical results affect the quality of phosphorus removal. The results show that if the polycrystalline silicon products are to be reduced to meet the requirements of the national standard of tertiary phosphorus ≤7.74ppba, then for the simulation process established in this paper, P in SiHCl3 before and after rectification should be ≤2557 ppbw and 1.79ppbw, respectively.