多晶硅表面菜花控制的研究

Study on Control Polysilicon Surface Cauliflower

棒状多晶硅的还原过程受进料量、进料配比、温度和气场等因素的影响,硅棒表面形貌也受到温度和物料在还原炉内分布的影响。通过还原炉内硅棒加载电流、炉筒壁面光洁度、进料喷嘴结构对菜花的影响进行研究,结果表明:(1)加载电流适宜,使硅棒表面温场分布均匀,且T≤Tmax,可减少硅棒表面菜花;(2)炉筒壁越光洁,菜花占比及电单耗越低;(3)进料喷嘴口径变小、高度增加,多晶硅横梁菜花降低,但前期易倒棒,而螺旋形喷嘴可降低硅棒表面菜花及还原炉倒棒率。

The reduction process of rod- shaped polysilicon was affected by the amount of feed,ratio of feed,temperature and gas field,and the surface morphology of silicon rods was also affected by the surface temperature of silicon rod and the feed distribution in the reducing furnace. The effects of the load current in silicon rods,the bright and clean of furnace wall and the structure of feed nozzle on the surface cauliflower were discussed. The results showed that the appropriate load current in silicon rods was made the surface thermal field of silicon rods distribution uniformity,and T≤Tmax,the surface cauliflower on silicon rods reduced. The wall of furnace was more bright and smooth with the lower cauliflower ratio and electricity consumption. The feed nozzle diameter decreased and height increased,the surface cauliflower in beam of silicon rods would decrease,the downfallen of silicon rods was easier in the early stage of the polysilicon production. The spiral nozzle can uniform the distribution of feed,both to reduce the surface cauliflower of silicon rods and avoid reducing downfallen rods in furnace.