Acceleration effect of CuCN in Ag electrode position for metal interconnection

Abstract

The addition of CuCN accelerated the deposition rate in cyanidebased Ag electroplating. The catalytic effect came from the highorder complexation of Cu with the free CN2- ions in electrolyte. It changed the equilibrium state of the electrolyte, presented as an increase in the amount of Ag(CN)2- compared to Ag(CN)32-. Because Ag(CN)2- could be reduced more easily, Ag electroplating was accelerated. FT-IR analysis showed the equilibrium change with the increase in Ag(CN)2- peak with CuCN addition. For superfilling, it is necessary to localise the complexation on Cu surface. ？ The Electrochemical Society.