Effect of Alternating Ar and SF6/C4F8 Gas Flow in Si Nano-Structure Plasma Etching
Lei Chen, Vincent K. Luciani, Houxun H. Miao
Si is very reactive to normal plasma etchants such as fluorine based chemicals and the reactions are inherently isotropic. To fabricate small and/or high aspect ratio nanoscale structures in Si, anisotropic profile is necessary. SF6 combined with C4F8 has been demonstrated as a good gas combination for anisotropic Si etching . In this study, Ar gas was introduced into the etching chamber to improve Si etching rate. In addition to mix Ar with F etching gases directly, an alternating Ar and F gas flow process was proposed. It is interesting to see that the Si etching profile, etching rate and etching selectivity are all improved by alternating Ar bombardment and SF6/C4F8 etching steps. The Si etching rate is determined by the Ar treatment step in alternating Ar and F two step process.
, Luciani, V.
and Miao, H.
Effect of Alternating Ar and SF6/C4F8 Gas Flow in Si Nano-Structure Plasma Etching, Microelectronic Engineering, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=906648
(Accessed December 3, 2023)