Abstract: Boron trifluoride is an important doping ion source for semiconductor ion implantation. In order to achieve electronic level requirements, purification technologies for boron trifluoride have been paid more attention. The commonly used purification methods were compared, such as cold trap, cryogenic rectification, selective adsorption, chemical conversion and combined methods. Cold trap technology had the superiorities of simple operation and low cost, but the amount of impurities from it was high. Cryogenic rectification had better separation result, but its energy consumption was large and operating conditions were strict. Selective adsorption and chemical conversion technologies had simple conditions, however, the performance of the adsorbent was not stable and the adsorption efficiency needs to be improved. Based on the purification background of high abundance boron trifluoride, the selective adsorption and cryogenic rectification combined method was emphasized. The purity of boron trifluoride obtained was not less than 99.995%. At last, a combined technology of cold trap, adsorption and cryogenic rectification was proposed. The purified gas obtained from it could be applied to electronics industry.

Key words: electronic gas, boron trifluoride, purification, cryogenic rectification, adsorption

摘要： 三氟化硼气体是半导体离子注入的重要离子掺杂源。为了达到电子级气体纯度的要求，三氟化硼气体的纯化技术研究具有重要意义。文中对三氟化硼气体的纯化工艺技术，即冷阱法、低温精馏法、选择性吸附法、化学转化法和多种工艺耦合联用进行了对比，分析各种工艺的优缺点： 冷阱法操作简便，成本低，但纯度不够； 低温精馏法分离效果好，但能耗大，操作条件要求比较严格；选择性吸附和化学转化法操作简易，设备安全，但吸附剂性能不太稳定，吸附效率有待提高。结合高丰度三氟化硼气体的纯化除杂背景，重点介绍选择吸附与低温精馏耦合联用工艺，纯化后的三氟化硼气体纯度可以达到99.995%。提出冷阱、物理吸附、化学转化以及精馏结合的方法，得到的高纯气体可以应用于电子工业领域。

关键词: 电子气体, 三氟化硼, 纯化, 低温精馏, 吸附