高纯电子级四氟化硅中恒沸物及金属杂质的去除

The Removal of Azeotropes and Metal Impurities from the High Purity Silicon Tetrafluoride in Electronic Grade

针对高纯电子级四氟化硅中卤代硅烷恒沸物及金属杂质难以去除的两大难题,采用溶剂萃取精馏法,通过评价5种萃取剂的萃取能力,筛选出一种非极性萃取剂。通过萃取剂的弱氢键作用,使卤代硅烷恒沸物分离至1×10^(-6)以下。同时,利用静电除尘器和新型离子脱除吸附剂,可以使金属杂质含量脱除至50×10^(-9)以下,同时又能保证四氟化硅不发生分解。基于上述方法,高纯电子级四氟化硅的产业化满足了安全环保、高效生产、质量稳定的要求。

In order to solve two problems of the purification of high purity silicon tetrafluoride in electronic grade, namely the difficulty of halogenated silanes and metal impurity removals, this paper proposed the solvent extraction distillation method. After the evaluation of extraction performances of five extractants, one kind of the nonpolar extractant has been selected. Based on the weak hydrogen bond interaction, the halogenated silanes have been separated to below 1×10 -6 . By the way of electrostatic precipitator and novel adsorbents of metal, we can control the metal impurities to below 50×10 -9 and inhibit the decomposition of silicon tetrafluoride. By the above-mentioned methods, the manufacture of the high purity silicon tetrafluoride in electronic grade can meet the requirements of safety, green environment, high efficiency and good quality.