Global warming evaluation of Chamber cleaning gases by new indicators, CEWN and CETN
Sekiya, Akira; Okamoto, Sayuri
(National Institute of Advanced Industrial Science and Technology (AIST) , Tsukuba, Ibaraki, Japan)
Dealing with the global warming is still big issue because the Earth temperature has been rising. Semiconductor and liquid crystal industries have been used long-lived fully fluorinated compounds that have high global warming effects. The long-term evaluation of global warming caused by the use of these gases has to be paid much more attentions. On the other hand, evaluation metric is quite important to get scientifically reliable results. In this paper, using LCCP (Life Cycle Climate Performance) data of our previous work, CVD chamber cleaning gases are evaluated by new global warming indicators, CEWN1) (Carbon Dioxide Equivalent Warming Number), CETN2) (Carbon Dioxide Equivalent Temperature Change Number), and s-CETN2) (square-Carbon Dioxide Equivalent Temperature Change Number ). CEWN evaluates based on radiative forcing as GWP3). CETN and s-CETN are based on the global surface temperature rise by Shine’s equation4). CEWN and CETN compare GHGs by unifying the removal rate of each gas from the atmosphere, while s-CETN unifies the ratio to the total amount of the global warming of each gas. They provide fair index of global warming to each GHG. LCCP data is analyzed using GWP, CEWN, CETN, and s-CETN and compared. Results show that CEWN, CETN, and s-CETN are as easy-to-use as GWP. Further, the relation of CEWN, CETN, s-CETN values with the climate impact is clearer than that of GWP values. According to those new indicators, the order of global warming is C2F6 > C3F8 > NF3>> COF2. In the case where 16% 5) of NF3 production releases into atmosphere, the global warming of NF3 is comparable with C3F8. The paper includes: a) the explanation about CEWN, CETN, and s-CETN. b) the LCCP results of global warming analyses by various indicators, such as CEWN, CETN, s-CETN, GWP, and so on. Literature: 1) A. Sekiya, and S. Okamoto, J. Fluorine Chem., 131 (2010) 364-368. 2) A. Sekiya, and S. Okamoto, 20th Winter Fluorine Conference, St. Pete Beach, FL, Jan. 9-15, 2011. 3) IPCC Climate Change 2007. 4) Shine, et al., Clim. Change, 68, (2005), 281-302. 5) R. F. Weiss, et al., Geophys. Res. Lett., 35 (2008) L20821.