CF4 decomposition using inductively coupled plasma: effect of power frequency

The performance evaluation of CF₄ decomposition efficiency using 2- and 4-MHz power supplies was carried out as a function of the power, the pressure, the flow rate, and the quantity of O₂ addition. When the 2- and 4-MHz power supplies were used, almost complete CF₄ removal was achieved at 2.0 and 3.0 kW, respectively, when the CF₄ flow rate was 0.20 normal liters per minute. The optimum O₂/CF₄ ratio should be in the range of 1.0∼1.25 in order to decompose CF₄ efficiently. The CF₄ decomposition efficiency using the 2-MHz power supply was significantly higher than that of the 4-MHz power supply under the same power, pressure, and flow rate. Significant amounts of byproducts such as COF₂ and CO were identified by the Fourier transform infrared spectrophotometer analysis in addition to CO₂.