Silicon nitride etch characteristics in SF6/O2 and C3F6O/O2 plasmas and evaluation of their global warming effects

Low Global Warming C4H3F7O Isomers for Plasma Etching of SiO2and Si3N4Films

“…Among them, replacing PFCs with lower GWP gases is considered the ultimate solution. − Studies have been reported on hydrofluorocarbons, unsaturated fluorocarbons, iodofluorocarbons, oxygen-containing fluorocarbons, fluoro-ethers, and fluoroalcohols to replace PFCs. − The GWP can be reduced by introducing iodine, hydrogen, or oxygen atoms in fluorocarbon molecules. − Iodine atoms have a weak bond with fluorocarbons and are easily decomposed in the atmosphere . Hydrofluorocarbons such as C 3 HF 5 , C 3 H 3 F 3 , CH 2 F 2 , and C 4 H 9 F reduce GWP because the hydrogen in these molecules induces the formation of non-global warming HF in plasma etching processes. − Fluorocarbon gases containing oxygen atoms in C 5 F 10 O, C 3 F 6 O, and c-C 4 F 8 O molecules are also being developed as potential alternatives to PFCs. − A small fraction of oxygen atoms in these molecules reduce GWPs and lifetimes by converting PFCs into CO, CO 2 , and COF 2 molecules while minimizing the side effects . The fluoro-ether- and fluoro-alcohol-containing hydrogen and oxygen have significantly lower GWPs than PFCs because the hydrogen atoms and the unsaturation bonds serve to increase the reactivity to hydroxyl radicals in the troposphere .…”

Plasma Atomic Layer Etching of SiO2 and Si3N4 with Low Global Warming C4H3F7O Isomers

“…The GWP of fluorocarbon molecules such as hydrofluorocarbons, oxygen-containing fluorocarbons, fluoro-ethers, and fluoro-alcohols can be reduced by introducing hydrogen or oxygen atoms. − In plasma etching processes, hydrogen in molecules such as CH 2 F 2 , C 3 HF 5 , C 3 H 3 F 3 , and C 4 H 9 F reduces GWP by forming non-global warming hydrogen fluoride (HF) molecules. − The presence of oxygen in molecules such as C 3 F 6 O, C 5 F 10 O, and c -C 4 F 8 O reduces GWP by converting PFCs into low-GWP molecules such as CO, CO 2 , and COF 2 . − Owing to their low-GWP, fluoro-ethers and fluoro-alcohols containing hydrogen and oxygen are gaining popularity as PFC alternatives. ,,, A few research groups have recently investigated fluoro-ethers and fluoro-alcohols as potential replacements for conventional PFCs in plasma etching processes. According to a previous study, fluoro-ethers in RIE silicon oxide etching can reduce global warming effects by 50–90% when compared to conventional PFC, C 4 F 8 .…”

Low energy elastic scattering of electrons from hexafluoropropene (C3F6)

“…The role of these molecules in the environment is also important, since their presence in the atmosphere expedites the effects of global warming because of their long atmospheric lifespan, large global warming potential (GWP100) over a 100 years' horizon, and strong infrared absorption. Therefore, research on the effects of PFC gases has been actively conducted to reduce the emission of these gases [6][7][8] to the atmosphere. In recent years, studies on the reduction of emission, decomposition, recycling, and replacement of the PFC gases have been attempted [6][7][8][9][10].…”

“…Therefore, research on the effects of PFC gases has been actively conducted to reduce the emission of these gases [6][7][8] to the atmosphere. In recent years, studies on the reduction of emission, decomposition, recycling, and replacement of the PFC gases have been attempted [6][7][8][9][10]. While scrubbing can reduce the emission of the PFC gases by destruction of the unreacted PFC gases and its byproducts at the exhaust produced during the etching process, it is difficult and expensive to completely decompose of these gases.…”