Development of Greenhouse Gases Measurement Standards to Achieve High Metrological Qualities for Evaluation of Pollutant Efficiency

Abstract

The control of greenhouse gases (GHGs) emission is one of the most critical environmental challenges facing all countries worldwide. CO2, the most representative greenhouse gas, is the primary GHG emitted through human activities, and the regulation of its emission has been an international issue. However, certain non-CO2 GHGs possess global warming potentials (GWPs) as high as tens to even ten thousands times that of CO2. For example, fluorinated greenhouse gases (F-GHGs), including CF4, C2F6, C3F8, C4F8, CHF3, CH2F2, SF6, NF3 and so on, have been widely used as etching process or chamber cleaning gases in semiconductor-related industries. Due to their high GWPs, F-GHGs are the most potent and longest lasting type of anthropogenic GHGs. Therefore, it has been an international goal to reduce the emissions of F-GHGs as well as other GHGs into the atmosphere. To evaluate the effectiveness of an F-GHG abatement system, measurement standards are needed for accurate and reliable quantification of the F-GHG emissions. CMS/ITRI is developing primary reference gas mixtures (PRMs) for high GWP GHGs, such as CF4, SF6 and NF3, to achieve the highest metrological qualities in gas concentration measurement. The production of gas mixtures follows ISO 6142: 2001, and the quality system is in compliance with ISO Guide 34: 2009. These PRMs can be used as primary standards to calibrate analyzers, and can act as the source of metrological traceability when performing instrument certification or validation. They can also be applied to check the accuracy of commercial infrared spectra installed in Fourier transform infrared (FTIR) spectrometers for quantification to evaluate the destruction or removal efficiency (DRE) of F-GHG abatement equipment in electronics manufacturing.