Low-κ organic layer as a top gate dielectric for graphene field effect transistors

We demonstrate the characteristics of dual gated graphene field effect transistors using a thin layer (similar to 7 nm) of parylene-C as a top-gate dielectric. Our devices exhibit good dielectric properties with minimal doping, low leakage current (similar to 10(-6) A/cm(2) at +/- 2 V), and a dielectric constant of similar to 2.1. Additionally, Raman spectroscopy did not reveal any process induced defects after dielectric deposition. Electrical characterization performed in air showed a carrier mobility of similar to 5050 cm(2)/Vs with hysteresis less than 30 mV during top gate operation (-2.5V to 2.5 V) which indicates that parylene and its interface with graphene does not have a significant amount of trapped charges. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4711776]