Electrical characteristics of graphene wrinkles extracted by conductive Atomic Force Microscopy and electrical measurements on kelvin structures

One of the key deliverables of using graphene as a channel in transistors is to achieve low source and drain parasitic contact resistance. Careful characterization of the surface of graphene is needed in order to improve understanding of the metal to graphene interface. In this paper, we employ conductive Atomic Force Microscope (C-AFM) to characterize the electrical properties of these wrinkles as a function of the applied force. At low forces, the wrinkles are more conductive than flat regions and at high forces the wrinkles have similar conductance as the flat regions. Graphene devices were fabricated and the total resistance of graphene in these devices was measured to be in the range 2Ω to 10MΩ. Additional research is planned to investigate if the wrinkles impact the electrical contact resistance of large area structures.