Ruthenium and Rhodium Vertical Interconnect Formation Using Gas Phase Electrodeposition

This paper presents localized gas phase electrodeposition of ruthenium (Ru) and rhodium (Rh) species into vertical interconnects. A spark discharge generates gas ions and charged species of the desired metal, which are transported by a gas flow and form a plasma jet. Prior lateral nano-bridge growth is further developed and enables the localized metal species deposition into vertical interconnect openings. This approach is additive and saves rare materials during processing. The process allows precise adjustment of the diameter, airgap size, and top finishing bump of the vertical interconnect.