應用霍式紅外光譜法調查半導體廠製程危害性氣體

Investigation of Semiconductor Work Place Airborne Chemicals by Fourier Transform Infrared Spectroscopy

了解半導體廠有害物之濃度和來源，可作為即時監控改善及安全衛生防護工作之參考。開放光徑和密閉腔式霍氏紅外光譜儀可即時有效監測半導體廠酸性氣體、全氟碳氫化合物（PFCs）及有害有機溶劑蒸氣。清淨室內主要污染物為異丙醇及丙酮，主要可能來自於擦拭及機台保養維修，而金屬蝕刻機台進行預防保養時，於刮除蓋上粉末及去離子水擦拭機台內壁時HCN濃度較高。另低壓氮化矽機台測得高濃度之NH3，需特別注意處理問題以免污染作業環境或發生白煙現象; 矽化鎢機台尾氣管線測得矽甲烷， 由於具自燃爆炸之危險性，管線累積及處理需特別注意其安全性。此外乾式洗滌塔（EDWARDS GRC Model DI50）之量測結果，對金屬蝕刻機台所排放HCl、BCl3及CCl4之處理效率可達99%，然對CF4尚無處理效果。

Identification and quantification of hazardous chemicals are essential for protecting the work place environment of semiconductor wafer fabrication factories. An open-path fourier transform infrared spectrometer (FTIR) and a close-cell FTIR were utilized to investigate the airborne acids, organics and perfluorinated compounds (PFCs). Isopropanol and acetone, common rinse solvents for tool maintenance and surface cleaning of equipment and work benches, were found as the major airborne contaminants in clean rooms. During preventive maintenance of metal etchers, hydogen cyanide was out-gasing from the processes of chamber-wall-deposition scrubbing and DI water wiping. High concentration of ammonium was found in the exhaust effluents of low pressure nitride CVD tools. The ammonium will create higher opacity smoke, emitted from house scrubber , if mixed with acid exhaust in the main duct. Exhaust of tungsen silicide CVD was also consisted of loss amount of explosive silane. The treatment efficiency of Edwards GRC model DI50 dry scrubber was 99% for HCl, BCl3 and CCl4 of metal etcher exhausts while its treatment efficiency for CF4 was nearly zero according to this study.