Low Resistance Metal Contacts to MoS2 Devices with Nickel-Etched-Graphene Electrodes

We report an approach to achieve low-resistance contacts to MoS2 transistors with the intrinsic performance of the MoS2 channel preserved. Through a dry transfer technique and a metal-catalyzed graphene treatment process, nickel-etched-graphene electrodes were fabricated on MoS2 that yield contact resistance as low as 200 Omega center dot mu m. The substantial contact enhancement (similar to 2 orders of magnitude), as compared to pure nickel electrodes, is attributed to the much smaller work function of nickel-graphene electrodes, together with the fact that presence of zigzag edges in the treated graphene surface enhances tunneling between nickel and graphene. To this end, the successful fabrication of a clean grapheneMoS(2) interface and a low resistance nickelgraphene interface is critical for the experimentally measured low contact resistance. The potential of using graphene as an electrode interlayer demonstrated in this work paves the way toward achieving high performance next-generation transistors.