Electrical resistivity evolution in electrodeposited Ru and Ru-Co nanowires

摘要

Nanoscale ruthenium(Ru)-based materials are promising replacements for existing multilayered Cu interconnects in integrated circuits.However,it is not easy to apply the results of previously reported studies directly to the electrochemical damascene process because the previous studies have mainly focused on thin flms by dry deposition.Here,we report the electrical resistivity and microstructure of electrodeposited Ru nanowires.We estimate that the resistivity value of a 10 nm diameter Ru nanowire to be71.6μΩcm after analyzing the resistivity values of individual nanowires with various diameters.Furthermore,we investigate the electrical properties of Ru_(x)Co_(1-x)nanowires where x is 0.04–0.99 at.%as possible replacements of the current Ta N barrier structures.Over the entire composition range,the resistivity values of alloys are much lower than that of the conventional Ta N.Additionally,Ru and Ru-alloy nanowires surrounded by dielectric silica are thermally stable after 450°C heat treatment.Therefore,the nanoscale Ru and Ru-Co alloys possessing low resistivity values can be candidates for the interconnect and barrier materials,respectively.