Pulse plating of copper germanide

Electrodeposition of copper germanide (Cu3Ge) thin films from an alkaline tartrate-complexed electrolyte is described. Current pulsing is shown to enable co-deposition of copper and germanium in the stoichiometric ratio Cu:Ge=3:1, while providing smooth and compact electrodeposits. The presence of epsilon-Cu3Ge phase with a monoclinic crystal structure is confirmed by X-ray diffraction of the as-deposited films. After annealing, Cu3Ge films exhibit an electrical resistivity of 45 mu Omega cm; a value higher than previously reported resistivity of e-beam evaporated Cu3Ge films (similar to 10 mu Omega cm). The higher electrical resistivity of the electrodeposited Cu3Ge films is attributed to smaller grain size and elevated impurity levels. (C) 2013 AIP Publishing LLC. [http://dx.doi.org/10.1063/1.4801470]