CF_4 Decomposition Using Low-Pressure Pulse-Modulated Radio Frequency Plasma(<Special Issue>Advanced Fusion of Functional Fluids Engineering)

CF_4 is one of the most stable gases among perfluorocompounds (PFCs) whose decomposition is extremely difficult. In this study, CF_4 decomposition was investigated using a pulse-modulated radio frequency (RF) plasma of 2 MHz, which is applicable to plasma etching and novel functional material manufacturing processes. When the absolute pressure and 100% CF_4 and 99.5% O_2 flow rates were set at 80Pa and 0.1 and 0.2 NL/min, respectively, almost complete CF_4 decomposition was achieved at the pulse modulation frequency range of 25 kHz to 99 kHz. The analysis of the by-product of CF_4 decomposition was carried out using a CO_2 gas analyzer and a Fourier transform infrared spectrophotometer (FTIR) with a pulse modulation frequency of 75 kHz. It was known that 10%, 50% and 24% of CF_4 are converted to CO, CO_2 and COF_2, respectively. It was considered that the remaining 16% of carbon is converted to carbon particles or other organic substances.