Abatement characteristics of N2O in low-pressure plasma reactor

The abatement characteristics of N2O were investigated in a plasma reactor positioned in front of a vacuum pump. Fourier transform infrared (FTIR) spectroscopy was used for evaluating the destruction and removal efficiency (DRE) and the identification of byproducts. The concentration of NO x (NO and NO2) was quantified by using an NO x analyzer. The DRE of N2O was enhanced by increasing the power or decreasing the N2O flow rate. A higher pressure yields a higher DRE of N2O and a lower concentration of NO x in the destroyed N2O. For understanding this phenomenon, the discharge characteristics were analyzed by using optical emission spectroscopy (OES). The spatial distribution of emission spectra from the discharge in a mixture of N2O and Ar gases was measured by varying the pressure. The mechanisms underlying the pressure effect on the N2O DRE and NO x concentration are discussed in terms of the electron density and the concentration of O radicals.