▎ 摘　　要

The parasitic resistance of different source/drain metals for top-gated graphene field-effect transistors was extracted by fitting the measured I-D-V-G data with a resistance model and was found to be a significant part of the total resistance of graphene field-effect transistors. The results show that Ti/Au gives relatively large contact resistance, about 7500 Omega.mu m. Ni/Au contact shows better result compared to Ti/Au, which is around 2100 Omega.mu m. The lowest contact resistance was given by Ti/Pd/Au, which is around 750 Omega.mu m. The contact resistivity for Ti/Pd/Au source/drain contact is around 2 x 10(-6) Omega.cm(2), close to state of the art GaAs technology. (C) 2011 American Institute of Physics. [doi:10.1063/1.3614474]