Chemical-Mechanical Planarization Issues in Patterning Copper and Aluminum Interconnects with Magnetic Liners

摘要

Chemical-Mechanical Planarization (CMP) of conductors is a key process in Damascene patterning of advanced interconnect structures. This paper presents various CMP issues in the Damascene patterning of copper and aluminum interconnects with magnetic liner materials. The effect of alternative commercial slurries, pads, and post-CMP cleaning alternatives are discussed, with removal rate, scratch density, surface roughness, dishing, erosion and particulate density used as performance metrics. Electrochemical measurements and surface analysis are used in delineating the fundamental mechanisms involved and differences between use of conventional conducting liners and the unique magnetic liners described. Model slurries are used to assist in delineating between alternative phenomenological mechanisms.