Synthesis of Diamond-like Carbon as a Dielectric Platform for Graphene Field Effect Transistors

The platform for supporting two-dimensional (2D) materials such as graphene has a critical influence on the electronic properties of the materials it supports. Here we report on the filtered cathodic vacuum arc deposition (FCVAD) of atomically flat diamond-like carbon (DLC) films with varied C sp3/sp2 content ratio by modulating the parameters of substrate bias voltage, then used as a dielectric platform for supporting graphene. By doing this, an all-carbon DLC-graphene heterostructure would be formed. Through characterizing this heterostructure and constructing graphene field effect transistors (FETs) on DLC, it was shown that graphene on DLC platforms had less doping from the substrate and improved FET carrier mobility compared with that of graphene on SiO2/Si substrate. Moreover, the graphene on different DLC platforms exhibited an increased FET mobility (up to ∼7032 and 5558 cm-2 V-1 s-1 for hole and electron, respectively) with the increase of C sp3/sp2 bond fraction in DLC which could be tuned by the negative bias voltage applied to the deposited substrates in the FCVAD synthesis of DLC here.