title: Effects of experimental parameters on NF(3) decomposition fraction in an oxygen-based RF plasma environment.
abstract: Clean procedure is one of the major emitters of perfluorinated compounds (PFCs) in semiconductor manufacturing. Nitrogen trifluoride (NF(3)) is increasingly the process gas of choice for eliminating PFC emissions. However, its toxic to human and similar global warming potential compared to most other PFCs made NF(3) warranted much more investigation. This study demonstrated a radio-frequency plasma system for decomposing NF(3). The effects of experimental parameters: input power, O(2)/NF(3) ratio, operational pressure and NF(3) feeding concentration on NF(3) decomposition fraction (eta(NF3)) and energy efficiency E(NF3) were examined in detail. The analytical results demonstrated that the NF(3) was almost completely decomposed (>99%) at input power=30W, [NF(3)](in)=1.0% and eta(NF3) increased with input power. However, adding O(2) to the system inhibited NF(3) decomposition and decreased E(NF3). Moreover, eta(NF3) and E(NF3), decreased with gradually increasing operational pressure. Notably, increasing the NF(3) feeding concentration increased molecule density, reducing eta(NF3), but increasing E(NF3). Furthermore, the products detected in the NF(3)/O(2)/Ar plasma system were NO(2), NO, N(2)O, SiF(4), N(2) and F(2). Potential reaction pathways in the oxygen-based NF(3) plasma environment were built-up and elucidated.
authors.affiliation: Department of Bioenvironmental Engineering, Chung Yuan Christian University, No. 22, Pu-Jen, Pu-Chung Li, Chung-Li 320, Taiwan, ROC. yafen@url.com.tw
authors.forename: Ya-Fen
authors.initials: YF
authors.lastname: Wang
authors.forename: Lin-Chi
authors.initials: LC
authors.lastname: Wang
authors.forename: MinLiang
authors.initials: M
authors.lastname: Shih
authors.forename: Cheng-Hsien
authors.initials: CH
authors.lastname: Tsai
mesh_terms: D004787:Environmental Pollution / Q000517:prevention & control*; D005459:Fluorides / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D007221:Industry; D007700:Kinetics; D017672:Nitrogen Compounds / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry*; D011846:Radio Waves; D012666:Semiconductors; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods
chemical_list: D017672:Nitrogen Compounds; D005459:Fluorides; D010100:Oxygen