Bottom-up Filling of Damascene Trenches with Gold in a Sulfite Electrolyte

Published

August 19, 2018

Author(s)

Daniel Josell, Thomas P. Moffat

Abstract

Superconformal Au deposition is demonstrated in a Na3Au(SO3)2 + Na2SO3 electrolyte including Bi3+. Micromolar additions of the Bi3+ to the electrolyte catalyze the reduction of Au(SO3)23- based on hysteretic voltammetry and rising chronoamperometric transients indicating accelerated Au deposition rates. Void-free bottom-up filling of Damascene trenches is achieved for a range of Bi3+ concentrations. In the presence of significant convection the bottom-up filling is accompanied by near-perfect passivation of the field, resulting in deposition that resembles through-mask plating in the recessed features. The observed behavior is discussed in the context of previously described mechanisms for superconformal electrodeposition.

Citation

Journal of the Electrochemical Society

Pub Type

Journals

Keywords

gold, superfill, trench, interconnect, bottom-up, superconformal

Citation

Josell, D. and Moffat, T. (2018), Bottom-up Filling of Damascene Trenches with Gold in a Sulfite Electrolyte, Journal of the Electrochemical Society (Accessed October 14, 2025)