Electrodeposition and Microstructure Characterization of Bimetallic Copper-Silver Films from the Methanesulfonic Acid Baths

Abstract

In this work, the bimetallic copper-silver deposits with variable compositions are prepared by electrodeposition from the methanesulfonate bath containing chloride ions. The precipitation of AgCl in this acid copper-silver bath can be avoided by the introduction of thiourea (TU) as the complexing agent. The composition and microstructure of such deposits are significantly affected by the introduction of TU, silver ion concentration, and deposition potential. The silver content varying from 0.7 to 43 w/o (weight percent) in the deposits is effectively adjusted by the systematic variation in the electrolyte composition and current density. The microstructures, such as the silver content, grain size, crystalline preferential orientation, and roughness of this series of Cu-Ag deposits are systematically compared for future electronic applications.

Electrochemical Synthesis of Nanocrystalline CuAg Coatings on Stainless Steel from Cyanide-Free Electrolyte

“…Many researchers are looking for cyanide-free baths due to the limitations of employing cyanide ions in the industry. Some work focuses on acidic sulphate baths [27,28], ammonia solution [29,30], hydrazine sulphate [31], methanesulfonic acid baths [32], protic ionic liquid [33], and pyrophosphate-iodide electrolyte [24]. However, the results are not encouraging.…”

Effects of Thiourea and Allyl Thioura on the Electrodeposition and Microstructures of Copper from Methanesulfonic Acid Baths

“…Thiourea is one of important additives in the electroplating of metals and alloys. [21][22][23][24][25][26][27][28][29] While the influences of thiourea in the acidic copper plating bath have been extensively studied and discussed, [21][22][23][24][25][26][27] there are relatively few reports focusing on the effects of its derivative, allyl thioura. 30 Based on the above ideas, a systematic comparison study on the influences of thiourea and allyl thioura on the electrodeposition behavior and Cu microstructures in the methane-sulfonic acid (MSA) bath is important.…”