Using an extractive Fourier transform infrared spectrometer for improving cleanroom air quality in a semiconductor manufacturing plant.
A mobile extractive Fourier transform infrared (FTIR) spectrometer was successfully used to locate, identify, and quantify the "odor" sources inside the cleanroom of a semiconductor manufacturing plant. It was found that ozone (O(3)) gas with a peak concentration of 120 ppm was unexpectedly releasing from a headspace of a drain for transporting used ozonized water and that silicon tetrafluoride (SiF(4)) with a peak concentration of 3 ppm was off-gassed from silicon wafers after dry-etching processing. When the sources of the odors was pinpointed by the FTIR, engineering control measures were applied. For O(3) control, a water-sealed pipeline was added to prevent the O(3) gas (emitting from the ozonized water) from entering the mixing unit. A ventilation system also was applied to the mixing unit in case of O(3) release. For SiF(4) mitigation, before the wafer-out chamber was opened, N(2) gas with a flow rate of 150 L/min was used for 100 sec to purge the wafer-out chamber, and a vacuum system was simultaneously activated to pump away the purging N(2). The effectiveness of the control measures was assured by using the FTIR. In addition, the FTIR was used to monitor the potential hazardous gas emissions during preventative maintenance of the semiconductor manufacturing equipment.
Li
Shou-Nan
SN
Center for Environmental, Safety and Health Technology, Industrial Technology Research Institute, 11F, Bldg. 51, 195-10 Sec. 4 Chung-Hsing Road, Chutung, Hsinchu, Taiwan 310, ROC. SNLi@itri.org.tw
Chang
Chin-Ta
CT
Shih
Hui-Ya
HY
Tang
Andy
A
Li
Alen
A
Chen
Yin-Yung
YY
D016902:Air Pollution, Indoor / Q000032:analysis*; D005459:Fluorides / Q000032:analysis; D006801:Humans; D007221:Industry; D009812:Odorants / Q000032:analysis*; D010126:Ozone / Q000032:analysis; D011786:Quality Control; D012666:Semiconductors; D017655:Silicon Compounds / Q000032:analysis; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*; D013624:Taiwan; D014691:Ventilation / Q000379:methods*
D017655:Silicon Compounds; D010126:Ozone; C049321:silicon tetrafluoride; D005459:Fluorides