Unsaturated Fluorocarbons in the Etching Process, Environmental Benefit, Technical Hurdles

Environmental concerns regarding saturated hydrocarbons has resulted in unsaturated hydrocarbons in the etching process such as C
₄
F
₆
. Higher costs and more exacting environmental resist conditions have made this difficult. It has been noted though, in several studies, the addition of additives can make these unsaturated processes practical with more than a 70% decrease in ozone altering emissions. Additives such as CH
₂
F
₂
, Argon, and C
₆
F
₆
, the later, hexafluorobenzene with a potential 97% reduction in emissions have been promised .Experimentation with unsaturated chemicals and several additives is presented in this paper as well as an analysis of their practicality. Results are in table and graphic form and illustrate possible utilization of these techniques on a process scale.