Fabrication and characterization of CVD-grown graphene based Field-Effect Transistor

In this work, we present both fabrication process and characterization of graphene field-effect transistors. Large scale monolayer graphene was grown by chemical vapor deposition (CVD) on Cu foils and transferred over pre-patterned back-gated devices on Si/SiO₂ substrate. Scanning electron microscopy, Raman spectroscopy and Hall effect measurement were used for characterizing graphene quality before and after the transfer. It was found that monolayer graphene with a low defect density and hole mobility up to 3180cm²/Vs at n=1.3·10¹² cm^-2, could be obtained. For device characterization, devices with different gate length were discussed. We report an intrinsic current gain cut-off frequency (ft ) of 15.5 GHz and maximum oscillation frequency of 12 GHz, deduced from the S-parameters measurements for device with gate length of 100 nm. This study demonstrates the potential of CVD-grown graphene for high speed electronics in combination with a technological process compatible with arbitrary substrates.