Jun-Hyun Kim, Chang-Koo Kim
Perfluoro carbon (PFC) plasmas, which are mainly used for plasma etching of SiO2 contact holes, have high global warming potentials (GWPs). As an alternative to PFCs, heptafluoroisopropyl methyl ether (HFE-347mmy) was used for SiO2 etching. HFE-347mmy have a significantly lower GWP (~ 350) than those of the conventional PFCs. In this study, SiO2 was etched in a HFE-347mmy/Ar plasma, and its etch characteristics was investigated. The etching characteristics of SiO2 in the HFE-347mmy/Ar plasma were studied in terms of the angular dependence of etch rates. The angular dependence of the SiO2 etch rates was obtained using the specially designed Faraday cage system. The normalized etch yield (NEY) curves showed maxima at angles between 50 and 70?, indicating that physical sputtering was the main contributor to the etching of SiO2 in HFE-347mmy/Ar plasmas. This work revealed the feasibility of using HFE-347mmy/Ar plasmas in SiO2 etching as an alternative to PFC plasmas.
Angular dependence, Etch rate, Etch yield, Fluorinated ether plasma, Perfluoro carbon plasma, Faraday cage
Cite this paper
Jun-Hyun Kim, Chang-Koo Kim. (2019) Mechanism for Plasma Etching of SiO2 using Low Global Warming Potential Materials. International Journal of Chemistry and Chemical Engineering Systems, 4, 1-4