Ru electrodeposition and behaviors of additives for advanced technology nodes

Ru deposition is required for advanced technology nodes (< 32 nm) because it can improve the performance with low resistivity in nanoscale features. This study reports electrochemical reactions of Ru and behaviors of additives on Ru electrodeposition using cyclic voltammetry (CV) and linear sweep voltammetry (LSV). Ru³⁺ forms complexes, and the complexes are reduced on the Ru surface. It was confirmed that disodium 3,3′-Dithiobis(1-propanesulfonate) (SPS) could accelerate Ru deposition, and polyvinylpyrrolidone (PVP) could suppress Ru deposition. Also, NaBr showed suppression, and it can form a strong suppression layer with PVP. Focused ion beam (FIB) image shows the filling of Ru with those additives.