Ultralow contact resistivity in annealed titanium edge contacts for multilayered graphene

The structure dependence and electrical properties of a metal contact with multilayered graphene (MLG) have been investigated. We demonstrate the superiority of end- (or edge-) contact configurations for future three-dimensional (3D) interconnect applications. The contact resistivity of titanium end contacts can be lowered to 7.7 × 10−8 Ω cm2 by thermal annealing at 450 °C, which is 2 orders of magnitude lower than that of conventional top-contact configurations, and to the best of our knowledge, it is the lowest value ever reported for a pristine MLG. X-ray photoelectron spectroscopy (XPS) measurements revealed the formation of covalent-bonded titanium carbide as an interface layer between the metal layer and MLG.