三氟化氮纯化的新工艺

A new process for purifying nitrogen trifluoride

三氟化氮作为等离子蚀刻剂和化学气相沉积室的清洗气体,可根据粗三氟化氮气体中各组分的沸点及物理、化学性质的差异选择不同的纯化工艺及设备。研究了冷阱法、吸附法、改进的吸附法3种纯化工艺的优缺点,并提出了一种新的纯化工艺,即用碱液清除酸性杂质及用精馏的方法排除轻组分与残余重组分。实验结果表明,新的纯化工艺可获得三氟化氮体积分数大于99.9%的高纯度产品,从而能够满足半导体工业的要求。

For purification of nitrogen trifluoride(NF3) which is used as a plasma etchant and cleaning gas for chemical vapor deposition (CVD) chambers,a few purification methods and equipment may be chosen according to differences in boiling points and physico-chemical properties of NF3 and its impurities.After weighing the advantages and disadvantages of methods such as cold trap,adsorption and improved adsorption,a new purification process was proposed,in which the lye was utilized to remove acidic impurities and the distillation technique was used to separate off the light and heavy impurities.The results indicate that the new purification process may obtain highly pure produce of NF3 gas with its purity exceeding 99.9%,which can meet the needs of semiconductor industries.