▎ 摘　　要

Contact resistance is an important limiting factor for the on-state current of graphene based devices. In this paper, both transmission line method and four-probe method are applied to measure the contact resistance in graphene-metal (Cr/Au and Ti/Au) interface. The calculated contact resistivity values by both methods are concentrated at 10(4) Omega mu m(2). These two methods are compared and four-probe method showed higher stability. At last, the graphene-Ti/Au devices are annealed at 400 A degrees C with argon and hydrogen gas flow. After annealing, the contact resistivity values are reduced to 10(3) Omega mu m(2).