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

开发了一种新的氟、氯气体（如NF_3CF_4、BC1_3）无害化技术，为材料先进工艺中有毒气体的脱除提供了新的思路。氟化物气体是有毒的并且是在制造半导体的过程中使用的特殊类型的气体，并且它们的具体应用包括半导体的干法蚀刻、CVD系统的清洁、火箭燃料的氧化剂等。然而，由于像NF 3这样的氟化物气体是有毒的并且具有高度的化学稳定性，如果排放到大气中，它与二氧化碳气体和氟利昂气体一样，容易对全球变暖造成深远的不利影响。研究小组利用氟化物气体与金属氯化物和氧化物之间的化学反应，并建立了一种新技术，使半导体制造厂排放的废气中含有的氟化物气体直接转化为无害物质。实验结果表明，与燃烧处理方法相比，化学反应可以在80-400℃的较低温度下进行。其它有利的特征是可以在低温和大气压下进行连续处理，并且该方法是紧凑的，易于控制，并且以低的运行成本安全地操作。

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.