Electrochemical deposition of Cu and Ta from pyrrolidinium based ionic liquid

The electrochemical deposition of tantalum and copper has been investigated in 1-butyl-1-methylpyrroli- dinium bis(trifluoromethylsulfonyl)imide ([BMP][TFSA]) on both boron doped diamond (BDD) and copper substrates in order to realize nanometric Cu–Ta bilayer deposits. Electrochemical experiments have been performed at 125 ° C in a glove box, under nitrogen atmosphere. Gal- vanostatic runs and cyclic voltammograms performed at different scan rates have been carried out in order to de- termine the electroreduction path for tantalum and copper. Potentiostatic experiments were performed at the potential values corresponding to the voltammetric peaks and the samples obtained were analysed by SEM-EDX analyses. For both metals nanometric crystallites have been obtained. Cu–Ta deposits have been prepared by a dual bath tech- nique and were constituted by fine crystallites with average sizes in the range 50–100 nm. The elemental maps indicate a different distribution of Cu–Ta depending on the substrates