Abatement of perfluorocarbons with an inductively coupled plasma reactor

Preliminary tests using an inductively coupled plasma (ICP) reactor to abate ${\mathrm{C}}_{\mathrm{2}}{\mathrm{F}}_6,$ ${\mathrm{CF}}_4,$ and ${\mathrm{CHF}}_3$ show promising results. In conjunction with this, some of the operating parameters, which need to be considered when trying to obtain maximum abatement efficiency, are explored. Near 100% destruction efficiency (DRE) for the persistently fluorinated compounds (PFCs) mentioned earlier has been achieved with ${\mathrm{O}}_2$ as the additive gas. Similarly, the abatement of ${\mathrm{CF}}_4$ with ${\mathrm{CH}}_4$ and/or ${\mathrm{CH}}_{\mathrm{4}}{\mathrm{/O}}_2$ as the additive gas, has shown comparable results. For the non-${\mathrm{CF}}_4$ PFCs, like ${\mathrm{C}}_{\mathrm{2}}{\mathrm{F}}_6$ and ${\mathrm{CHF}}_3,$ the formation of ${\mathrm{CF}}_4$ as an abatement by-product was monitored and shown that it can be controlled by varying the operating parameters of the ICP reactor. The trends in the DRE observed while manipulating the ICP operating parameters such as ICP power, residence time, amount/type of additive gas, and Ar dilution, show that there are trade offs which must be taken into account. A quadrupole mass spectrometer was used for analyzing the abatement effluents.