Development of Harmless Disposal System of Fluoride and Chloride Gases by Chemical Reaction with Metal Oxide

开发了NF_3、CF_4、BC1_3等含氟、氯化物气体无害化的新工艺，建立了材料先进工艺中有毒气体脱除的新理念。氟化物气体是半导体制造过程中使用的有毒特殊气体，其具体应用包括半导体的干蚀刻，CVD系统的清洗，火箭燃料的氧化剂等。然而，由于NF3等含氟气体具有毒性和高度的化学稳定性，如果排放到大气中，很可能像二氧化碳气体和氟利昂气体一样，对全球变暖造成深远的不利影响。研究组利用氟化物气体与一种金属氯化物和氧化物发生化学反应的原理，开发了将半导体制造工厂排放的废气中的氟化物气体直接转化为无害物质的新技术。实验结果表明，与燃烧处理相比，在80 ~ 400℃的较低温度下可以进行化学反应。其他有利的特点是可以在低温常压下进行连续处理，并且该工艺结构紧凑，易于控制，运行成本低，可安全操作。

A new technology to make fluoride and chloride gases such as NF_3 CF_4 and BC1_3 harmless has been developed and a new concept on the removing of toxic gas to be used in the advanced process of materials has been established. The fluoride gases are toxic and special type of gases to be used in the process of manufacturing semiconductors and their specific applications include the dry etching of semiconductors, cleaning of CVD systems, the oxidation agent for rocket fuel etc. As a fluoride gas like NF3 is, however, toxic and highly chemically stable, if discharged into the atmosphere, it is liable to cause far-reaching adverse influences on global warning in the same manner as carbon dioxide gas and freon gas.The research team utilized the chemical reaction between fluoride gas and a metal chlorides and oxides, and established a new technology to make fluoride gas contained in the exhaust gas from semiconductor manufacturing plants convert directly into a harmless substance. Experimental results verify that the chemical reactions can be take place at substantially lower temperature of 80-400℃ as compared with the combustion treatment method. The other favorable characteristics are that continuous treatment is possible at a low temperature under atmospheric pressure, and that the process is compact easily controllable and safely operable at low running cost.