1999 年 42 巻 1 号 p. 31-36
Near-infrared laser diode spectroscopy at 1.74μm is applied to the detection of trace amounts of HCl in semiconductor process equipment such as an epitaxial growth reactor of Si. The application of the experimental system to different situations of HCl emissions is tested : the low-pressure condition is employed for residual gas monitoring, while the atmospheric pressure condition is used for reaction by-product monitoring. The detection limit of a 50-cm-long path cell is 1 ppm at low pressure (1.07×104 Pa) and 100 ppm at atmospheric pressure. A wide dynamic range of 1 ppm to 1% and a linear response to the HCl concentration are also obtained, both of which are favorable for system integration to manufacturing processes.
