Selective Chemical Vapor Deposition-Grown Ru for Cu Interconnect Capping Applications

A selective chemical vapor deposition process of a ruthenium (Ru) metal capping layer was investigated for Cu interconnects in ultralarge scale integrated circuits. X-ray fluorescence spectroscopy determined the Ru deposition selectivity as a function of the deposition temperature and substrate materials. The feasibility of the selective Ru metal capping layer in the Cu interconnects for nanoelectronic applications was checked via a comprehensive evaluation including both electrical and reliability.