Back-gated microwave field-effect transistors based on transferred CVD-grown graphene
Résumé
Graphene based transistors have drawn growing interest from both industries and Laboratories [1-3]. 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∙1012cm-2, could be obtained. For device characterization, we report an intrinsic current gain cut-off frequency (ft) of 13.5GHz and maximum oscillation frequency of 8GHz, deduced from the S-parameters measurements. This study demonstrate the potential of CVD-grown graphene for high speed electronics in combination with a technological process compatible with arbitrary substrates [4,5].