Abatement of CF4 and CHF3 byproducts using low-pressure plasmas generated by annular-shaped electrodes

Abstract

Three different driving schemes are tested for a plasma reactor designed to abate the greenhouse gases emitted by the semiconductor industry. The reactor and electrodes all have a concentric annular shape, which allows them to be easily connected to pre-existing pipelines without any disturbance to the exhaust stream. The destruction and removal efficiencies are measured for CF4 by varying the O2/CF4 ratio and pressure. The influences of adding O2 and H2O to the byproducts of the CHF3 abatement process are investigated by analyzing the spectra resulting from Fourier transform infrared spectroscopy measurements. Based on the experimental results we suggest an appropriate combination of driving scheme and reactant gas species for efficient and economical abatement of a mixture of CHF3 and CF4. Then, the optimal flow rate of the reactant gas is presented. Finally, the reduction rates for global warming emissions are estimated to demonstrate the feasibility of using our device for abatement of greenhouse gases emitted by the semiconductor industry.

Promoted CF4 Decomposition via Enhanced Tricoordinated Al Active Sites

“…At present, various methods, including plasma, combustion, and catalytic hydrolysis, have been developed for the decomposition methods of CF 4 . − Among them, catalytic hydrolysis is regarded as a promising method owing to its capability of high decomposition efficiency and large gas flux. − Al-based materials with abundant acidic sites are the most used catalysts in decomposition of CF 4 . − Song et al reported that the more the Lewis acid sites on the surface of Al-based catalysts, the stronger the ability to decompose CF 4 . Zhang et al found that the strong Lewis acid site of unsaturated tricoordinated Al (Al III ) was the main active site for CF 4 decomposition, indicating that more Al III active sites represent higher CF 4 decomposition activity.…”