The Limits of Detection for the Monitoring of Semiconductor Manufacturing Gas and Vapor Emissions by Fourier Transform Infrared (FTIR) Spectroscopy

To determine whether or not the Fourier transform infrared (FTIR) spectrometer is appropriate for industrial hygiene monitoring of the gases and vapors used in the semiconductor industry, the limits of detection (LOD) of these compounds were determined. The LODs were calculated using several widely used definitions to test whether the values obtained by the different methods would vary significantly. The experimental LOD values for the study compounds all were below their respective threshold limit values (TLVs®), and a significant difference between the LOD values calculated using the different definitions was noted. The FTIR spectrometer equipped with an indium antinomide/mercury cadmium telluride (InSb/MCT) sandwich detector, 20-m path length gas cell, and least squares fit (LSF) software is appropriate for monitoring semiconductor processing gases and vapors in the workplace.