Plasma etching methods using nitrogen memory species for sustaining glow discharge

摘要

Methods are described which comprise: providing a plasma etching apparatus having an etching chamber; disposing a substrate to be etched in the chamber; introducing N₂ gas and one or more process gases into the chamber; and etching the substrate, wherein the introduction of the N₂ gas is stopped prior to etching, and wherein etching comprises an initial plasma ignition wherein at least a portion of the N₂ gas remains present in the chamber during initial plasma ignition. Additional methods are described which comprise: providing a plasma etching apparatus having an etching chamber; disposing a substrate to be etched in the chamber; introducing N₂ gas and one or more process gases into the chamber; applying power to an electrode in the chamber such that an N₂ memory species is formed; and etching the substrate, where the introduction of the N₂ gas into the chamber can be stopped prior to etching. Other methods are also described which comprise: providing a plasma etching apparatus having an etching chamber; disposing a substrate to be etched in the chamber; introducing N₂ gas into the chamber; applying power to an electrode in the chamber such that an N₂ memory species is formed; removing the applied power from the electrode in the chamber; stopping the introduction of the N₂ gas into the chamber and introducing one or more process gases into the chamber; and etching the substrate.