Electrodeposited CoCu/Cu meta-conductor with suppressed skin effect for next generation radio frequency electronics

Multilayered Cu/CoCu metal-conductors were prepared by alternatively electrodepositing Cu and CoCu layers in the same electrolyte. The relationships between the phase structure, surface roughness, magnetic properties and the plating potential have been studied in details. Soft CoCu layers with low coercivity were obtained by selecting proper additives, which allowed the introduction of in-plane uniaxial magnetic anisotropy and negative permeability above 1.5 GHz. A transmission line consisting of 10 CoCu/Cu bilayers with near zero effective permeability was then designed and fabricated, which yielded >80% lower resistance at 10 GHz compared to a Cu transmission line in the same dimensions. This study offers a novel metal-conductor with suppressed eddy current loss and a low-cost method for next generation RF electronics.