Contact and via structures with copper interconnects fabricated using dual Damascene technology

Abstract

A novel submicron process sequence was developed for the fabrication of CoSi/sub 2//n/sup +/-Si, CoSi/sub 2//p/sup +/-Si ohmic contacts and multilevel interconnects with copper as the interconnect/via metal and titanium as the diffusion barrier. SiO/sub 2/ deposited by plasma enhanced chemical vapor deposition (PECVD) using TEOS/O/sub 2/ was planarized by the novel technique of chemical-mechanical polishing (CMP) and served as the dielectric. The recessed copper interconnects in the oxide were formed by chemical-mechanical polishing. (dual Damascene process). Electrical characterization of the ohmic contacts yielded contact resistivity values of 10/sup -6//spl Omega/-cm/sup 2/ or less. A specific contact resistivity value of 1.5/spl times/10/sup -8//spl Omega/-cm/sup 2/ was measured for metal/metal contacts.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>