Method of fabricating improved interconnect structure with a via gouging feature absent profile damage to the interconnect dielectric

摘要

An interconnect structure including a gouging feature at the bottom of the via openings and a method of forming the same, which does not introduce either damages caused by Ar sputtering into the dielectric material that includes the via and line openings, nor plating voids into the structure are provided. The method includes the uses of at least one infusion process that forms an infused surface region within a conductive material of a lower interconnect level. The infused surface region has a different etch rate as compared with the conductive material and thus in a subsequent etching process, the infused surface region can be selectively removed forming a gouging feature within the structure.