Characterization of interface interactions between Graphene and Ruthenium

To further understand the interaction of graphene-integrated interconnects, we focus on the interface characterization of graphene-ruthenium hybrid systems. A systematic characterization is performed to quantify the charge transfer between graphene and Ru. By studying the relative band alignment, we measure interface potential barrier height and report an effective work function of 4.9 eV. Carrier concentration of 1.9E13cm
⁻²
is obtained. Surface potential mapping suggests a downward shift of Fermi level in graphene valence band implying hole-doping on Ru substrate. Concurrent physical characterizations complement each other and fully support the conductivity gain demonstrated earlier.