Characteristics of Silver Electrodeposition Solution and Silver Film Fabricated by Electrodeposition with Additives for Interconnection

Abstract

As the electrodeposition reaction is a heterogeneous reaction including both material transfer and electrochemical reaction, this study tries to find out the reaction mechanism about Ag electrodepostion used as semiconductor interconnection using rotating disk electrode system (RDE system). Considering the environmental problem, non-cyanide Ag electrodeposition solution has been carried out. With varying the process conditions of a certain range including the rotating speed of RDE, applied voltage, and temperature etc., obtained the electrodeposition rate of Ag according to the reaction time. The rate determining step was clarified with the activation energy(Ea) of the electrodeposition reactions for the each process conditions estimated from Arrhenius Plot. Activation energy of Ag in the temperature range between 18°C and 32°C was 3.2kcal/mole. The electrodeposition rate of Ag seems to be controlled mass transport. With the electrodepositon solution mentioned above, the characteristics of silver thin film and bottom-up filling capability were investigated by DC or pulsed electrodeposition method. Especially, the effects of additives on the properties of bottom-up filling of Ag were studied.