Chemical Vapor Deposition of Mn and Mn Oxide and their Step Coverage and Diffusion Barrier Properties on Patterned Interconnect Structures

Chemical vapor deposition of bis(ethylcyclopentadienyl)manganese, (EtCp)2Mn, was performed on a patterned interconnect structure to obtain a thin conformal layer with a good diffusion barrier property for advanced Si devices. Deposition of (EtCp)2Mn on SiO2 formed a conformal layer of Mn oxide within a contact hole with a uniform thickness of 3 to 4 nm. Similar conformal formation of Mn oxide was obtained on SiO2 in the vias and trenches of a dual-damascene structure. The deposition of (EtCp)2Mn on Cu, however, formed a solid solution with Cu. The solute Mn migrated toward the interface of Cu/SiO2 to form Mn oxide.