The influence of graphene substrate on microstructures and electrical properties of vapor-deposited copper thin films

Due to the exceptional electrical properties, graphene (Gr) has shown remarkable potential in reducing the resistivity of Cu. However, the systematic studies on the influence of Gr on microstructure and electrical properties of Cu thin films are rare, which is particularly important for the application of Cu interconnection in integrated circuits. In this study, we investigated the growth characteristics and electrical performance of Cu films with consideration of Gr-Cu interactions. In contrast to the anticipated 20 % reduction in electrical resistivity for Gr/ Cu/SiO2/Si, the Cu/Gr/SiO2/Si unexpectedly demonstrates a 1018 % increase in electrical resistivity compared to Cu/SiO2/Si counterpart at 7 nm thickness. Our results suggested that the increased surface roughness induced by the weak interaction of Gr-Cu exacerbated the surface electron scattering, offsetting the advantages offered by the additional carrier transport channel provided by Gr. This finding underscores potential limitations in the application of Gr in micro-electronics interconnection.