光電廠乾蝕刻機台廢氣含氯衍生物量測技術與改善策略研究

Abstract

TFT-LCD之光電廠中乾蝕刻機台使用之氯氣及六氟化碳等特氣，於製程蝕刻反應過程後，產生之酸性製程廢氣經由酸排氣風管抽至局部處理設備作一次處理，達到削減溫室效應氣體目的，再排至廠務端之酸性濕式洗滌塔進行二次處理後排放，經調查發現這些特氣經局部處理設備燃燒室反應後，會產生含氯有機物等副產物，其排放至大氣環境中，將可能造成健康風險之問題產生。 研究初期針對不同型式之局部處理設備進行含氯衍生物調查發現，當含氯製程尾氣進入燃燒室前能先以水洗處理去除氯，將可有效降低後續燃燒反應產生之含氯有機物等副產物。另本研究透過氣相層析質譜儀分析來掌握光電廠內局部處理設備的排放特性，同時利用光游離偵檢器針對局部處理設備良窳進行評估判斷，篩選出異常局部處理設備並進行改善。研究結果發現當局部處理設備燃燒反應器溫度不足會造成有機氯化物與大量副產物產生，且當處理設備維護條件不佳的狀況，如多孔性陶瓷狀況、維護保養時程長短、天然氣送氣口微粒阻塞、天然氣訊號錯接等狀況，亦會導致大量有機氯化物產生。 透過此建立之含氯衍生物量測技術，未來可用於檢核光電廠乾蝕刻機台局部處理設備的維護狀況，訂定相關保養規範來維持其應有之處理效能，可有效降低由其產生之衍生危害風險。

TFT-LCD plant uses the chlorine and hexafluoride special gas in the dry etching machine, after the etching process, the wasted acidic gas exhausts by the exhaust duct to the local scrubber to achieve the purpose of greenhouse gases reduction, and the acidic gases then exhaust to central wet scrubbers facility-side for secondary treatment before emissions to the atmosphere. The survey found that the special gas treated by partial combustion chamber, some orgainc chlorine content by-products would emists to the atmosphere, that would harmful to human health. Initial stage of the study on chlorine derivatives treatment with different type of processing equipment found that washes the chlorine-containing process gases before put them into combustion chamber for chlorine remove can effectively reduce the generation of organic materials, such as chlorine by-product. Another purpose of this study is to find out the emission characteristics of local scrubber by GC-MS analysis. In the meanwhile, the study also use Photo Ionization Detector( PID) to evaluate the performance of local scrubber, and screen out and modify abnormal local scrubber. The results shows that when the temperature of partial combustion reactor processing equipment isn’t high enough, a large amount of chlorinated organic by-products will be generated. When the local scrubber isn't well maintained that would affect the ceramics conditions in equipment, the period of maintenance, natural gas aspirated particulate mouth obstruction, and natural gas detector’s signal is connect the wrong position, and result in the produce of large amount of organic chloride. With the establishment of chlorine derivatives measurement technique, detection the status of local processing equipment of dry etcher in photelectronic plant can be achieved in the future. The risk can be effectively eliminated by set up equipment maintenance regulation to maintain the treatment effectiveness of the equipments.