Microstructure and in-plane resistivity of Cu/Ni multilayers

The Cu/Ni multilayers were deposited using ion beam sputtering at room temp erature and 250 degrees C respectively. The microstructures of the multilay ers including interfacial roughness, grain size and growth direction have b een investigated by transmission electron microscopy and X-ray diffraction. The microstructure depends strongly on the substrate temperature and modul ation wavelength, bigger grain size and larger interfacial roughness were o btained when the multilayers were deposited at 250 degrees C, and the multi layers ceased to grow epitaxially due to the increasing defects in the mult ilayers. The resistivity of the multilayers is very sensitive to the micros tructure due to the size-effect. In order to study the influence of the mic rostructure to the resistivity, the in-plane resistivity of Cu/Ni multilaye rs was measured using four-point probe. The resistivity increases with high er substrate temperature, and it decreases when the modulation wavelength b ecomes short. The interfacial roughness and grain size have co-contribution to the resistivity. The interface scattering is the main factor that has e ffect on the resistivity of Cu/Ni multilayers.