Electrodeposition of Ru on Nanoscale Trench Patterns

Ru deposition in advanced technology nodes can improve performance by providing low resistance in nanoscale features. In this study, we reported the electrochemical reactions of Ru3+ on an Ru surface using multi-cyclic voltammetry (CV) and behavior of additives during Ru electrodeposition using linear sweep voltammetry (LSV) and potentiostatic measurements. Disodium 3,3'-dithiobis(1-propanesulfonate) (SPS), polyvinylpyrrolidone (PVP), and a bromide ion (Br-) were added for bottom-up filling. We investigated the suppression behavior of PVP. The current density and the onset potential of suppressor breakdown were affected by the suppressor concentration. PVP interacted synergistically with Br- and showed additional suppression. PVP formed a suppressing layer with Br- after formation of a bromide layer. SPS could reduce roughness during electrodeposition of Ru. Based on these results, nano-trenches were filled with Ru using the optimized additive condition.