矽甲烷供氣系統的尾氣處理效率改善研究

Abstract

一般業界在處理管路內殘留之矽甲烷(SiH4，Silane)尾氣時會將其以氮氣稀釋，再排放至燃燒箱內作常溫自燃反應，但此種方法的處理效率不佳。為了增加燃燒箱內SiH4的處理效率，本研究在燃燒箱內加裝了一支電熱棒，並探討加熱溫度和SiH4尾氣處理效率之間的關係。本研究首先先設計了ㄧ個SiH4供氣設備及燃燒箱，用來測試燃燒箱處理效率。本實驗以量測燃燒箱上下游的SiH4濃度，以及量測SiH4燃燒反應後所產生之SiO2粉塵的方式來評估燃燒箱內加熱器對SiH4氣體的處理效率。實驗結果顯示，SiH4處理效率會隨著電熱棒溫度的增加而提高。以SiH4氣體偵測器推估的處理效率顯示，常温時SiH4處理效率約為6.59 %，當燃燒棒的溫度增加至300 °C及400 °C時，處理效率會分別提升至40.41 %及48.82 %。而以SiO2粉塵採樣所評估的結果則顯示，未開啟電熱棒時，燃燒箱下游幾乎採集不到SiO2粉塵，亦即SiH4的處理效率不顯著。當加熱溫度達150 °C以上時則可採集到大量的粉塵。由上述結果可看出，在燃燒箱內增加溫度可確實提升管路內SiH4尾氣的處理效率。故本研究也建議在半導體與光電製程處理SiO2殘留尾氣時，應利用加熱方式增加燃燒箱內的溫度以提高其處理效率。

In the industry, the silane (SiH4) tail gas remained in the tubing is generally treated with nitrogen gas for dilution and then passed into the combustion chamber for a spontaneous combustion reaction under the room temperature. However, the treatment efficiency of this approach is low. In order to increase the SiH4 treatment efficiency in the combustion chamber, an electronic heating rod was installed in the combustion chamber, and the relationship between the heating temperature and the SiH4 treatment efficiency was also discussed. Firstly, the SiH4-providing equipment and a combustion chamber were designed for testing the treatment efficiency of the combustion chamber. The treatment efficiency was determined by measuring the SiH4 concentrations upstream or downstream of the combustion chamber and by measuring the amount of the dust from the SiH4 combustion reaction. Results show that the SiH4 treatment efficiency increases with increasing the temperature of the electronic heating rod. The results from SiH4 gas measurement show that the SiH4 treatment efficiency is only 6.59 % under room temperature. When the temperature of the electronic heating rod increased to 300 and 400 oC, the treatment efficiency was increased to 40.41 and 48.82 %, respectively. The results from SiH4 dust measurement show that when the electronic heating rod was switched off, there is nearly no dust downstream of the combustion chamber, which means that the treatment efficiency is poor. When the heating temperature was increased to 150 oC, a large amount of dust was observed. From the above results, it is seen that the treatment efficiency of SiH4 tail gas in the tubing indeed increases with increasing the temperature. Therefore, it is suggested that for the SiH4 tail gas treatment in the manufacturing process of semi-conductor or photoelectric industry, the temperature of the combustion chamber should be increased to increase it treatment efficiency.