Characterization of SiO(2) Plasma Etching with Perfluorocarbon (C(4)F(8) and C(6)F(6)) and Hydrofluorocarbon (CHF(3) and C(4)H(2)F(6)) Precursors for the Greenhouse Gas Emissions Reduction

This paper proposes the use of environmentally friendly alternatives, C(6)F(6) and C(4)H(2)F(6), as perfluorocarbon (PFC) and hydrofluorocarbon (HFC) precursors, respectively, for SiO(2) plasma etching, instead of conventional precursors C(4)F(8) and CHF(3). The study employs scanning electron microscopy for etch profile analysis and quadrupole mass spectrometry for plasma diagnosis. Ion bombardment energy at the etching conditions is determined through self-bias voltage measurements, while densities of radical species are obtained using quadrupole mass spectroscopy. The obtained results compare the etch performance, including etch rate and selectivity, between C(4)F(8) and C(6)F(6), as well as between CHF(3) and C(4)H(2)F(6). Furthermore, greenhouse gas (GHG) emissions are evaluated using a million metric ton of carbon dioxide equivalent, indicating significantly lower emissions when replacing conventional precursors with the proposed alternatives. The results suggest that a significant GHG emissions reduction can be achieved from the investigated alternatives without a deterioration in SiO(2) etching characteristics. This research contributes to the development of alternative precursors for reducing global warming impacts.