Aniruddha Joi

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 e-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 μΩ cm; a value higher than previously reported resistivity of e-beam evaporated Cu3Ge films (∼10 μΩ cm). The higher electrical resistivity of the electrodeposited Cu3Ge films is attributed to smaller grain size and elevated impurity levels.