Post-etch treatment of plasma-etched feature surfaces to prevent

Abstract

Disclosed herein is a post-etch treatment for plasma etched metal-comprising features in semiconductor devices. The post-etch treatment significantly reduces or eliminates surface corrosion of the etched metal-comprising feature. It is particularly important to prevent the formation of moisture on the surface of the feature surface prior to an affirmative treatment to remove corrosion-causing contaminants from the feature surface. Avoidance of moisture formation is assisted by use of a high vacuum; use of an inert, moisture-free purge gas; and by maintaining the substrate at a sufficiently high temperature to volatilize moisture. The affirmative post-etch treatment utilizes a plasma to expose the etched metal-comprising feature to sufficient hydrogen which is in a kinetic state permitting reaction with residual halogen-comprising residues on the etched surface, while maintaining the etched feature surface at a temperature which supports volatilization of the byproducts of a reaction between the active hydrogen species and the halogen-comprising residues. For an etched copper surface, if moisture forms on the etched surface prior to an affirmative treatment to remove corrosion-causing contaminants, it is very important to avoid contact of the etched surface with pollutants which are capable of forming copper carbonates and/or copper sulfates.