Hydrogen-based Plasma Research Articles

Total toxicity equivalents emissions of SF 6, CHF 3, and CCl 2F 2 decomposed in a RF plasma environment

Sulfur hexafluorine compound (SF 6), trifluoromethane (CHF 3) and diclorodifluoromethane (CCl 2F 2) are extensively used in the semiconductor industry. They are global warming gases. Most studies have addressed the effective decomposition of fluorine compounds, rather than the toxicity of decomposed by-products. Hence, the concepts of toxicity equivalents (TEQs) were applied in this work. The results indicated that HF and SiF 4 were the two greatest contributors of TEQ to the SF 6/H 2/Ar plasma system, while F 2 and SiF 4 were the two greatest contributors to the SF 6/O 2/Ar system. Additionally, SiF 4 and HF were the two greatest contributors of TEQ to both the CHF 3/H 2/Ar and CHF 3/O 2/Ar plasma systems. HF and HCl were the two greatest contributors of TEQ to the CCl 2F 2/H 2/Ar plasma system, and Cl 2 and COCl 2 were the two greatest contributors to the CCl 2F 2/O 2/Ar system. HCl and HF can be recovered using wet scrubbing, which reduces the toxicity of these emission gases. Consequently, the hydrogen-based plasma system was a better alternative for treating gases that contained SF 6, CHF 3 and CCl 2F 2 from the TEQs point of view.