▎ 摘　　要

We report on an experimental demonstration of graphene-metal ohmic contacts with contact resistance below 100 Omega mu m. These have been fabricated on graphene wafers, both with and without hydrogen intercalation, and measured using the transmission line method. Specific contact resistivities of 3 x 10(-7) to 1.2 x 10(-8) Omega cm(2) have been obtained. The ultra-low contact resistance yielded short-channel (source-drain distance of 0.45 mu m) HfO2/graphene field effect transistors (FETs) with a low on-resistance (R-on) of 550 Omega mu m and a high current density of 1.7 A/mm at a source-drain voltage of 1V. These values represent state-of-the-art (SOA) performance in graphene-metal contacts and graphene FETs. This ohmic contact resistance is comparable to that of SOA high-speed III-V high electron mobility transistors. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4719579]