Microwave Plasma Torch Abatement of NF3 and SF6

Summary form only given. Fluorinated compounds (FCs) are essential to the semiconductor manufacturing process for plasma chamber cleaning and plasma etching. Because FCs have extremely long atmospheric lifetimes and are strong infrared absorbers, efforts have been undertaken to identify methods to reduce atmospheric emissions. Many methods for FC abatement have been suggested, such as wet and burning scrubber, and low-pressure plasma device. In this work, an atmospheric pressure microwave plasma torch as a new method for PFC abatement was presented. Detailed experiments were conducted on abatement of NF₃ and SF₆ in terms of destruction and removal efficiency (DRE) using Fourier transform infrared (FTIR). Swirl gas, compressed air, for stable plasma was injected with main mixture of N₂, NF₃ or SF₆, and C₂H₄ as an additive gas into the microwave plasma torch. Destruction and removal efficiencies of up to 99.1% for NF₃ were achieved without an additive gas by applying microwave powers from 0.8 to 1.2 kW. Also, DRE determined from FTIR data for SF₆ was obtained 90.1% using applied microwave power of 1.4 kW. Experimental results indicate that the microwave plasma abatement device for PFC destruction can successfully eliminate FCs in the semiconductor industry.